Are you experiencing engine trouble? We'll help you pinpoint the problem.
Here is a list of faults that may or may not be related to a malfunction of the ethanol conversion kit. This list is not exhaustive but may be of great help.
The engine does not start immediately after installation.
| Polarity reversal | The connection of the terminals in the male connectors of our wiring harness needs to be reversed. |
| Faulty ECU | As a last resort, double-check that it's not the ECU fuse. |
| Blown fuse | Check if the problem is caused by a fuse. |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to check if the control unit is receiving injection times; if it's a problem of reversed polarity, you'll see it immediately because the missing cylinder will be absent from the display of the PC or smartphone application. |
Immediately after installation, the engine is not running on all cylinders.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Engine control unit: an overly rich fuel mixture can cause this type of problem. | In principle, all our units are sent pre-set for your engine, so if the mixture is too rich, there is a good chance that this is due to a faulty ignition (spark plugs or coils). If you find the setting too rich then modify the setting (potentiometer) using the OBD for Starflex boxes, or by modifying the additional % on the 2.0 Wifi box. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Reversed polarity on 1 male connector of our harness | Check which of the male connectors in our harness has the lug with the red wire inserted on the reverse side compared to the other connectors, and if possible depending on the type of connector you need to pull out the two lugs to put them back on the right side. |
| Incorrect connection on an injector | It is possible that a connector is not properly engaged on the injector. |
| Faulty ECU | Incorrect handling during your polarity check can damage the ECU |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to check if the control unit is receiving injection timings on all cylinders. |
Right after installation, my engine is emitting so much white smoke that I can no longer see behind the vehicle.
| Short circuit in the wiring harness causing the injector to open continuously | This is generally the case with this type of problem: either the wiring harness is in contact with a very high heat source (EGR valve), or it has been pinched and damaged while reinstalling the intake manifold, for example, which causes the injector to remain open continuously. The ECU can be damaged as a result of this oversight. |
| Faulty ECU | Incorrect handling during your polarity check can damage the ECU. |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Verifiable and/or adjustable with the 2.0 Wifi box | The ECU cuts fuel injection to the affected cylinder. This is immediately visible on the PC screen or smartphone app, and furthermore, the color of the affected cylinder corresponds to the wire colors in the ECU harness, making it easy to identify the cylinder with the problem. |
The engine suddenly wouldn't start.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Battery dead or defective | Replace the battery if it no longer holds a charge; don't forget to check that the alternator is working properly. |
| Key transponder or key that is faulty or defective | If one of the two is faulty, the starter motor will turn but the engine will not start. |
| TDC sensor faulty or defective | In principle, this fault is detected by the ECU; the fault code is present in the OBD. |
| Oil leak on the TDC sensor | Remove the sensor to check that it is dry; if there is oil present, the gearbox will need to be disconnected to replace the crankshaft oil seal located behind the flywheel. |
| Inertia shock switch triggered | Not all vehicles are equipped with this switch, but you could spend hours searching if you don't think of it. |
| ECU immobilization | This needs to be checked with a diagnostic tool equipped to access this information. |
| Faulty coolant temperature sensor (ECT) | Engine temperature is crucial information for the ECU, which (depending on the make) may prevent the engine from starting if it doesn't have this information. |
| Temperature error corrector for Starflex HS or defective housings | Check the engine temperature using the OBD scanner. If in doubt, reconnect the original connector without disassembling anything to verify. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Faulty ECU | As a last resort, double-check that it's not the ECU fuse. |
| Blown fuse | Check if the problem is caused by a fuse. |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to check if the control unit is receiving injection times |
The engine is difficult to start when cold.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Battery dead or defective | Replace the battery if it no longer holds a charge; don't forget to check that the alternator is working properly. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Dirty or faulty throttle body | Check the throttle body for play. If it's dirty, the engine may stall at idle. |
| Air temperature sensor (IAT) faulty or defective | A significant deviation in this sensor reading can disrupt the engine's proper starting. |
| TDC sensor faulty or defective | In principle, this fault is detected by the ECU; the fault code is present in the OBD. |
| Oil leak on the TDC sensor | Remove the sensor to check that it is dry; if there is oil present, the gearbox will need to be disconnected to replace the crankshaft oil seal located behind the flywheel. |
| Faulty coolant temperature sensor (ECT) | Incorrect temperature information can cause this type of problem. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Case: an excessively lean mixture setting can cause this type of problem. | The Starflex unit has a very efficient cold start program based on temperature, but this cannot be modified. Note that if this problem occurs after several months of proper operation on E85, the issue rarely originates from the unit itself, but rather from wear parts, as mentioned in the other possibilities discussed in this chapter. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| If this problem occurs after 3 or 4 tanks of E85, the control unit is not injecting enough fuel during cold starts. | If this problem occurs after 3 or 4 fill-ups with E85, it may be due to the control unit not injecting enough fuel when cold. The Starflex unit has a very efficient cold start program based on temperature, but this cannot be modified; you have two options: – Putting 7L of SP95 in your tanks can correct this problem. – Install our temperature error corrector (if your probe has 2 wires, otherwise it is not suitable) For the 2.0 Wi-Fi version, a simple adjustment is all that's needed. On the PC application, simply increase the percentage for the relevant temperature in the cold start section. Remember to confirm with the provided password, otherwise this change will not be applied. If this problem occurs long after switching to E85, there is a strong chance that it stems from a worn part, one of the other possibilities discussed in this chapter. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
The engine starts when cold and then stalls.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure information can cause engine malfunctions. |
| Battery dead or defective | Replace the battery if it no longer holds a charge; don't forget to check that the alternator is working properly. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Dirty or faulty throttle body | Check the throttle body for play. If it's faulty, the ECU will usually go into limp mode quickly. If it's dirty, the engine may stall at idle. |
| TDC sensor faulty or defective | In principle, this fault is detected by the ECU; the fault code is present in the OBD. |
| Oil leak on the TDC sensor | Remove the sensor to check that it is dry; if there is oil present, the gearbox will need to be disconnected to replace the crankshaft oil seal located behind the flywheel. |
| Faulty coolant temperature sensor (ECT) | Incorrect temperature information can cause this type of problem. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Case: an excessively lean mixture setting can cause this type of problem. | If this problem does not occur with unleaded fuel, it is due to the control unit not injecting enough fuel. – With the Starflex unit, this cannot be modified. Installing our error-correcting device can fix this problem, or you must put in 7 liters of unleaded gasoline before filling up with E85. – With the 2.0 Wifi box, you just need to increase the % at cold start. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | Adjust the time and quantity settings within the relevant temperature range. |
The engine misfires when cold.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| TDC sensor faulty or defective | In principle, this fault is detected by the ECU; the fault code is present in the OBD. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Case: an excessively lean mixture setting can cause this type of problem. | If this problem does not occur with unleaded fuel, it is due to the control unit not injecting enough fuel. – With the Starflex unit, this cannot be modified. Installing our error-correcting device can fix this problem, or you must put in 7 liters of unleaded gasoline before filling up with E85. – With the 2.0 Wifi box, you just need to increase the % at cold start. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Fast idle pump faulty or defective | Some engines are equipped with a fast idle pump; check if it is working or if the hose is damaged. |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It's possible to check the fuel being sent to the injectors, and often if it's an ignition problem, you'll notice a significant irregularity in the fuel flow across all cylinders. |
The engine is running poorly, but there's no engine warning light.
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Too much oil in the engine | Oil manages to enter the cylinders. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Dirty or faulty throttle body | Especially at idle, a dirty throttle body can cause the engine to stall. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| Blown or defective cylinder head gasket | Perform a CO2 test |
| Temperature error corrector for Starflex HS or defective housings | Check the engine temperature using the OBD scanner. If in doubt, reconnect the original connector without disassembling anything to verify. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Fast idle pump faulty or defective | Some engines are equipped with a fast idle pump; check if it is working or if the hose is damaged. |
| Faulty ECU | Very rare but possible |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure that the ECU will have to compensate for by increasing injection corrections. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to check the operation sent to the injectors; if one or more cursors on the PC or smartphone application are moving inconsistently, the color of the cursor that corresponds to the color of our beam will help you easily identify the cylinder concerned. The coils and spark plugs need to be swapped with another cylinder to then check if the problem moves to another cylinder in order to determine if it is an ignition or injection problem. If the cylinder remains the same, then we need to reverse the connection of our wiring harness with the neighboring cylinder to check if the problem moves in order to determine if the problem comes from the control unit/wiring harness or if it is the injector. |
The engine is difficult to start when hot
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | The problem often stems from the injectors or spark plugs. Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. If not, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform 30% worse than the original ones. Old injectors can also be sensitive to the dual opening created by the housing, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others; nobody goes there, so the station's tank empties very slowly, and the ethanol accumulates water created by condensation. If you put in fuel that is at the bottom of an almost empty tank, you will have a high percentage of water... Nothing better to seize up your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Air temperature sensor (IAT) faulty or defective | A significant deviation in this sensor reading can disrupt the engine's proper starting. |
| Faulty coolant temperature sensor (ECT) | Incorrect temperature information can cause this type of problem. |
| Temperature error corrector for Starflex HS or defective housings | Check the engine temperature using the OBD scanner. If in doubt, reconnect the original connector without disassembling anything to verify. |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Ethanol sensor subjected to excessive heat | Be careful that the ethanol sensor is not subjected to excessively high temperatures caused by the engine or exhaust (V6 and V8 in summer). |
| Ethanol container subjected to excessive heat | Place the ethanol conversion kit in a location that protects it from the high temperatures of the engine and exhaust (V6 and V8 engines in summer). |
The engine misfires when hot
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| TDC sensor faulty or defective | In principle, this fault is detected by the ECU; the fault code is present in the OBD. |
| Temperature error corrector for Starflex HS or defective housings | Check the engine temperature using the OBD scanner. If in doubt, reconnect the original connector without disassembling anything to verify. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It's possible to check the fuel being sent to the injectors, and often if it's an ignition problem, you'll notice a significant irregularity in the fuel flow across all cylinders. |
The OBD system is reporting a combustion fault on 1 cylinder.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Blown or defective cylinder head gasket | Check using a CO2 tester |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Reversed polarity on 1 male connector of our harness | |
| Incorrect connection on an injector | It is possible that a connector is not properly engaged on the injector. |
| Short circuit in the wiring harness causing the injector to open continuously | This can occur if the wiring harness comes into contact with a source of intense heat such as the exhaust, EGR valve, or air conditioning hose. |
| Faulty ECU | Incorrect handling during your polarity check can damage the ECU |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Verifiable and/or adjustable with the 2.0 Wifi box | The ECU cuts fuel injection to the affected cylinder. This is immediately visible on the PC screen or smartphone app, and furthermore, the color of the affected cylinder corresponds to the wire colors in the ECU harness, making it easy to identify the cylinder with the problem. |
The OBD system is reporting a combustion fault on several cylinders.
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Too much oil in the engine | Oil manages to enter the cylinders. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Dirty or faulty throttle body | Check the throttle body for play. If it's faulty, the ECU will usually go into limp mode quickly. If it's dirty, the engine may stall at idle. |
| Valve stem seals that are no longer sealing properly | They cause significant oil consumption and can randomly disrupt injection corrections at idle and also after prolonged deceleration. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Faulty ECU | Incorrect handling during your polarity check can damage the ECU |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It's possible to check the fuel being sent to the injectors, and often if it's an ignition problem, you'll notice a significant irregularity in the fuel flow across all cylinders. |
Unstable idle
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Dirty or faulty throttle body | Check the throttle body for play. If it's faulty, the ECU will usually go into limp mode quickly. If it's dirty, the engine may stall at idle. |
| Valve stem seals that are no longer sealing properly | They cause significant oil consumption and can randomly disrupt injection corrections at idle and also after prolonged deceleration. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Defective electronic accelerator | Very rare, but a faulty electronic accelerator pedal can cause this problem. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Incorrect connection on an injector | It is possible that a connector is not properly engaged on the injector. |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It's possible to check the fuel being sent to the injectors, and often if it's an ignition problem, you'll notice a significant irregularity in the fuel flow across all cylinders. |
The engine lacks power
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Defective electronic accelerator | A faulty electronic accelerator pedal can cause this problem. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
I have a hesitation in acceleration at low revs
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to check the operation sent to the injectors; if one or more cursors on the PC or smartphone application are moving inconsistently, the color of the cursor that corresponds to the color of our beam will help you easily identify the cylinder concerned. The coils and spark plugs need to be swapped with another cylinder to then check if the problem moves to another cylinder in order to determine if it is an ignition or injection problem. If the cylinder remains the same, then we need to reverse the connection of our wiring harness with the neighboring cylinder to check if the problem moves in order to determine if the problem comes from the control unit/wiring harness or if it is the injector. |
I'm experiencing jolts (missed) at the top of the towers
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| TDC sensor faulty or defective | In principle, this fault is detected by the ECU; the fault code is present in the OBD. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Faulty engine wiring harness or connector(s) | Check the wiring harness and connectors |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to check the operation sent to the injectors; if one or more cursors on the PC or smartphone application are moving inconsistently, the color of the cursor that corresponds to the color of our beam will help you easily identify the cylinder concerned. The coils and spark plugs need to be swapped with another cylinder to then check if the problem moves to another cylinder in order to determine if it is an ignition or injection problem. If the cylinder remains the same, then we need to reverse the connection of our wiring harness with the neighboring cylinder to check if the problem moves in order to determine if the problem comes from the control unit/wiring harness or if it is the injector. |
I have a "faulty emissions control system" message displayed on the dashboard.
| The ECU detected an engine fault | If this message appears on the dashboard, it means the ECU has detected an engine fault. The presence of this message doesn't necessarily mean the problem is caused by the ethanol conversion kit; it could be the cause, but like hundreds of other possibilities, you need to check the fault code with an OBD scanner to pinpoint the source of the problem. The ECU has hundreds of fault codes available to indicate even the smallest anomaly detected (sensor, wear parts, etc.). Electronic diagnostics using an OBD scanner are essential. So every time you have an engine fault, you will also get this message. |
For the first 10 minutes my engine emits a little white smoke
| That's normal, it's condensation present in the exhaust. |
Water is coming out of the exhaust pipe.
| That's normal, it's condensation present in the exhaust. |
The OBD is showing me a P0420 code: ineffective catalytic converter
| Catalytic converter clogged due to lack of high temperatures | If the vehicle is only used for short trips or city driving, the catalytic converter is rarely subjected to the high, continuous temperatures necessary to burn off carbon deposits. Driving on the highway for 20 minutes at 5000 rpm can resolve this issue. |
| Lambda sensor after the catalytic converter | We always start with this sensor because the catalytic converter is expensive. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Too much oil in the engine | Oil can travel up to the air intake and then clog the exhaust. |
| Check the compression | Insufficient compression leads to poor combustion and unburned fuel, as well as high pressure in the crankcase, causing oil to be drawn up and potentially clogging the catalytic converter. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty breather hose or breather hose | Oil enters the cylinders and clogs the catalytic converter. |
| Valve stem seals that are no longer sealing properly | Oil enters the cylinders and clogs the catalytic converter. |
The OBD is indicating a lean mixture (fault code P0171).
| Clogged or defective injectors | Injectors that are no longer delivering enough fuel, are spraying incorrectly, or are clogged. Have the injector spray pattern and flow rate checked. They may be clogged or partially blocked by a pasty carbon deposit. In this case, clean the nozzles with a cloth and a cleaner, taking care not to damage them. Please note that no injector cleaner added to the fuel tank will be effective for this type of clogging. Only dismantling the fuel rail and cleaning it manually or with an ultrasonic cleaner will completely remove this carbon deposit, which can sometimes completely clog the injector. |
| Fuel pump or fuel pressure regulator | If your fuel pump is no longer delivering enough fuel or if the pressure regulator is faulty, your ECU will have to compensate for this by increasing the injection timing. However, if this deficiency is too severe, your ECU will reach its maximum correction tolerance and illuminate the engine fault light to inform you that the mixture is too lean. |
| Air intake at the intake manifold | An air leak causes this type of engine fault. Possible causes include: intake manifold gaskets, injector seals, throttle body gasket, cracked manifold, damaged, improperly connected or disconnected air hose, canister, and EGR valve. This type of fault can be difficult to detect without a tool that allows you to inject smoke into the intake manifold, which quickly identifies leaks and their source. |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
| Faulty hose or canister | May cause an air leak |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Faulty ECU | Very rare but possible |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure that the ECU will have to compensate for by increasing injection corrections. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| Incorrect housing adjustment | If this problem occurs within 700 km of switching to 100% E85, the fuel injection system may need a slightly richer mixture. In France, if this warning light illuminates from April onwards, given the switch from E65 to E85, the mixture may be slightly lean; in this case, slightly increase the fuel mixture setting on the control unit. |
| Oil dipstick or cap more airtight | A leaky oil dipstick or cap will allow air into the engine, causing poor air pressure in the intake manifold, which will result in an air leak with fault code P0171. |
The OBD is indicating an overly rich mixture
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Faulty ECU | Very rare but possible |
| Incorrect housing adjustment | If this problem occurs after switching to 100% unleaded 95 or 98, the engine management system may require a slightly leaner fuel mixture. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
The OBD is indicating a lean mixture at idle
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
| Faulty hose or canister | May cause an air leak |
| Faulty ECU | Very rare but possible |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure that the ECU will have to compensate for by increasing injection corrections. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
The OBD is indicating an overly rich mixture at idle.
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Too much oil in the engine | Oil can travel up to the air intake and then clog the exhaust. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Valve stem seals that are no longer sealing properly | They cause significant oil consumption and can randomly disrupt injection corrections at idle and also after prolonged deceleration. |
| Faulty ECU | Very rare but possible |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
I've been consuming more than before lately.
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| Camshaft sensor faulty or defective | An engine fault indicator will be displayed. If one of these sensors malfunctions, this type of problem may occur. |
| Faulty coolant temperature sensor (ECT) | Incorrect temperature information can cause this type of problem. |
| This is possible if you only make short trips. | In cold weather, the engine takes longer to reach operating temperature; up to 60°C, an engine may be in "choke" mode. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
| Poor fuel quality | A hypothesis that should not be ruled out |
My LTFT (long-term fuel injection corrections) are too high at idle (warm engine).
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| Fuel leak | In principle, it is easily detectable by smell or leakage. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
| Faulty hose or canister | This can cause an air leak. |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It's possible to check the fuel being sent to the injectors, and often if it's an ignition problem, you'll notice a significant irregularity in the fuel flow across all cylinders. |
My LTFT (long-term fuel injection corrections) are too high at 2700 rpm (warm engine).
| Spark plugs | When switching to ethanol, the spark plugs must be changed every 30000 km to avoid any combustion problems. Always use original equipment manufacturer (OEM) parts. Iridium-coated spark plugs offer greater longevity. |
| Ignition coils | If they have more than 60000 km on them, the ignition coils are frequently the cause of misfires. When replacing them, be sure to use new spark plugs. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Lambda sensor before the catalytic converter | A lambda sensor that is too slow or faulty can cause this problem. – If it's a zirconium lambda sensor, check at idle with the engine warm that the sensor generally takes no more than 2 seconds to complete its waveform; otherwise, it's too slow and may be faulty. You should also check with an exhaust gas analyzer to ensure the emissions are within acceptable limits. – If it is a proportional (wideband) lambda sensor, check with an exhaust gas analyzer if the pollution is correct. |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
| Poor fuel quality | A hypothesis that should not be ruled out |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | It is possible to verify the function sent to the injectors. |
My duty cycle reaches 100%
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Verifiable and/or adjustable with the 2.0 Wifi box | Only the 2.0 Wifi unit allows for monitoring the duty cycle during operation to detect this problem; 100% means the injectors no longer have time to close between two sprays. |
| Check the operation of the ethanol conversion kit | For the Starflex case: – With the engine idling, open the housing and check if the green LED is lit; it should be lit by itself. – With the engine idling, open the housing and quickly turn the potentiometer(s) counterclockwise until they reach the stop (0); the engine should react (reduced speed and almost stalling). – You can also check via OBD if the STFT values change when you adjust the potentiometer, but depending on the brand, this isn't always instantaneous or noticeable. For the 2.0 box, you have the information about the percentage sent by the box, but to be certain you can proceed as follows: – With the engine idling and the PC connected to the device via Wi-Fi, note the injection time sent by the ECU, then set the device's setting to 0%, enter your password to validate the request, the engine should react, and check the injection times sent by the ECU, which should have changed a few seconds after validation (unless you have the ethanol sensor option and there is only unleaded in the tank, in which case the sensor will have a value close to 0, which does not cause any modification by the device). |
MAP too high > 0,45 bar
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Injector(s) | Check if the nozzles are clogged with a pasty carbon deposit that can build up over time. This deposit hardens in cold weather and can prevent the injector from spraying. Otherwise, the injectors can be tested on a bench. Always prioritize new injectors over cleaning and reconditioning. Never buy cloned injectors, which are much cheaper but only last three weeks and can sometimes perform more than 30% worse than the original ones. Old injectors can also be sensitive to the double opening created by the control unit, which can cause misfires and jerking. Avoid stations that sell their E85 at a much higher price than others. Since nobody uses them, the station's tank empties very slowly, and the ethanol absorbs water from condensation. If you fill up with fuel from the bottom of a nearly empty tank, you'll end up with a high percentage of water... Nothing better to seize your injectors, which will then need replacing. |
| catalyst | A blocked or broken catalytic converter can obstruct the flow of exhaust gases. From 2001 onwards, all ECUs detect this problem = Check Engine Light illuminates |
| Incorrect pressure in the fuel rail | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. Insufficient pressure will inevitably lead to a loss of power, excessive fuel injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. |
| Faulty fuel pump | For indirect injection systems, fuel pressure is one of the few pieces of information the ECU doesn't have, so the pressure can be incorrect and you won't see an engine warning light on the dashboard. A lack of pressure will inevitably lead to a loss of power, excessively high injection corrections, misfires, or even engine failure, preventing the engine from restarting. It is essential to test this with a fuel pressure tester. If the pump isn't working, check the fuse or relay first. |
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Blocked exhaust pipe | Not always, but frequently audible |
| Faulty mass airflow sensor (MAF) or manifold absolute pressure (MAP) sensor | Incorrect air flow or pressure readings can cause engine malfunctions. |
| Injector seals are faulty | Damaged injector seals cause fuel leaks and/or air leaks. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| Faulty fuel pressure regulator | In principle, only certain engines over 15 years old are equipped with it. |
| Valve seats that are no longer sealing properly | Causes include uneven idling, misfires, unburned fuel in the exhaust, excessive fuel consumption, likely indicating the engine is nearing the end of its life, high mileage, an old or neglected engine, or a poorly designed engine. |
| External fuel filter needs changing | If it is practically blocked, it can cause a drop in fuel pressure, thus limiting the pressure necessary for proper operation. |
| Some engines do not transmit the same values for this information, for example some Renault engines. |
The engine is overheating
| Blocked exhaust pipe | Not always, but frequently audible |
| Blown or defective cylinder head gasket | Perform a CO2 leak test |
| Coolant leak | Increase pressure to check |
| Faulty water pump | To check |
| faulty thermostat | Thermostat that remains closed |
| Faulty coolant temperature sensor (ECT) | Incorrect temperature information can cause this type of problem. |
| Temperature error corrector for Starflex HS or defective housings | Check the engine temperature using the OBD scanner. If in doubt, reconnect the original connector without disassembling anything to verify. |
| Verifiable and/or adjustable with the 2.0 Wifi box | The case's temperature sensor allows you to access this information on a PC or smartphone app via Wi-Fi. |
High idle speed or slowing down
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Dirty or faulty throttle body | Check the throttle body for play. If it's faulty, the ECU will usually go into limp mode quickly. If it's dirty, the engine may stall at idle. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| Defective electronic accelerator | A faulty electronic accelerator pedal can cause this problem. |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
Idle speed too high when hot
| Air intake | To locate an air leak, it is practically essential to have a smoke generator; otherwise, the search becomes very complicated. |
| Dirty or faulty throttle body | Check the throttle body for play. If it's faulty, the ECU will usually go into limp mode quickly. If it's dirty, the engine may stall at idle. |
| Faulty breather hose or breather hose | Oil is entering the cylinders through the intake, or if it's the hose, this can cause an air leak. |
| EGR valve stuck or faulty | A damaged EGR valve will continuously allow exhaust gases to pass through, creating an air leak and thus disrupting the ECU's operation. |
The engine consumes a lot of oil
| Check the compression | A compression issue could be causing this problem. The difference between the highest and lowest values should not exceed 20%. |
| Faulty breather hose or breather hose | This could be the cause of oil consumption |
| Oil leak on the TDC sensor | Remove the sensor to check that it is dry; if there is oil present, the gearbox will need to be disconnected to replace the crankshaft oil seal located behind the flywheel. |
| Valve stem seals that are no longer sealing properly | They cause significant oil consumption and can randomly disrupt injection corrections at idle and also after prolonged deceleration. |
| Oil leak | To check |
| Depending on the engine, this may be normal. | Check with the manufacturer's data; some engines have high fuel consumption from the factory. |
On the PC or smartphone application, the cursors become inconsistent when the engine malfunctions.
| This usually stems from the ignition system, so either the spark plugs or the coils. |
(2.0 Wifi) On the PC or smartphone application, one cursor remains frozen while the others work
| This means the ECU has cut off fuel injection and ignition to one cylinder due to a combustion fault. Typically, when the problem is persistent, the engine warning light on the dashboard will initially flash upon restarting and then remain continuously illuminated. This indicates that the ECU has detected a combustion problem on one cylinder (when it flashes) and, as a safety measure, cuts off fuel injection and ignition to the affected cylinder. The OBD scanner will display a fault code corresponding to a combustion problem on the specific cylinder. ---------- – With the PC and smartphone app, when you start the engine, you can see all the sliders that are active, based on the injection timing sent by the ECU to the injectors. Once the ECU cuts off operation on the cylinder with the problem, you'll see that the affected slider remains frozen while the others continue to function. The color of this slider corresponds to the wire colors in our wiring harness to simplify troubleshooting. Example: Problem on cylinder 2, cursor color grey on PC and smartphone app, in this case the corresponding wire colors on our harness will be the grey wire and the red wire for the male connector and the white/grey wire and the red wire for the female connector, so you can quickly identify the cylinder that has a fault. Once you've identified the cylinder, it's very simple; all you have to do is swap the components (spark plug, coil, wiring harness connections) with the other cylinders. Example: Problem on cylinder 1 / blue cursor on the PC and smartphone app, in this case perform the following tasks: – Reversal of our wiring harness, which includes blue and white/blue wires on cylinder 1 (blue) with cylinder 2 (grey) – Swap the spark plug of cylinder 1 (blue) with that of cylinder 3 (green) – Swap the ignition coil of cylinder 1 (blue) with cylinder 4 (brown) – Clear the engine fault code using the OBD scanner (In this example, we match the order of the cylinders with the order of the slider colors, but please note that this is to simplify the example because the connection of our harness does not have a cylinder order; you are not obliged to connect the blue wire harness with cylinder 1, our control unit works regardless of the connection order) Then restart the engine and check the operation of the sliders again; one of them will remain fixed when the ECU has cut off the faulty cylinder; the color of the slider will allow you to target the cylinder with the element you have reversed. – The indicator light is fixed on blue, so cylinder 2 indicates a problem with the control unit or the wiring harness. In this case, open the control unit and connect the wiring harness to the connector intended for 5- to 8-cylinder engines, then restart the engine. If the problem is resolved, the control unit is malfunctioning. If the blue light remains fixed, the problem is with the wiring harness. – The cursor is fixed on the grey color, therefore cylinder 1 = injector, or significant air leak at the manifold gasket, valve, piston… – The indicator is fixed on the green color, therefore cylinder 3 = faulty spark plug, replace them all – The cursor is fixed on the brown color, therefore cylinder 4 = ignition coil, change them all as well as the spark plugs |
(2.0 Wifi) On the PC or smartphone application, one cursor exhibits completely inconsistent behavior.
| Identify the cylinder with wires of the same color as the faulty slider. – Check if there is a terminal that is incorrectly inserted on the male connector that is connected to the engine harness or on the female connector that connects to the injector. – Check the condition of the white connector that plugs into the housing – Open the case – Disconnect the harness from the housing and check on the white connector there are small windows to see if the terminal is properly inserted, check that it is properly inserted for each wire. – Connect the white connector to the neighboring 10-pin connector which is dedicated to cylinders 5 to 8. If the problem is solved in this case, the control unit may be defective, unless it is an intermittent fault which can complicate the search for fault. For this, try again to reconnect it to the 1 to 4 cylinder connector to be sure that the problem returns immediately. – Reverse the wiring of the harness with the wires of the same color as the faulty slider with the neighboring cylinder to see if the problem moves. If it moves = ignition or injector problem If the faulty cursor remains the same = faulty control unit wiring harness |
On the PC or smartphone app, one cursor is missing even though it is normally connected.
| If you have just completed the assembly, the cylinder with the wires of the color of the missing slider has reversed polarity or is incorrectly connected. – Check if the male terminals of the connector are not reversed compared to the others – Check if a terminal is incorrectly inserted in the male connector of our wiring harness for the cylinder in question |
(2.0 Wifi) On the PC or smartphone application, intermittently, especially when the engine is idling and I give it a little gas, a cursor sometimes displays an inconsistent value. The cylinder involved may differ each time this happens, but I don't feel any misfires.
| If the cylinder changes each time and the acceleration is smooth, it's nothing serious; it could be due to incorrect information being received by the PC or smartphone app. |
(2.0 Wifi) On the PC or smartphone app, intermittently, especially when the engine is idling and I give it a little gas, a cursor sometimes displays an inconsistent value. The cylinder involved may differ each time, but I feel one or more misfires when it happens.
| If the engine is cold and this problem is new, the causes could be: – Candles – Reels – Injector(s) that are stuck or clogged – Lack of valve sealing when cold – Air intake – Oil leak spreading into the air intake manifold (valve stem seals, breather, low compression, oil overfill) If the engine is cold and this has been happening since the initial installation of the control unit, the cause is most likely: – The mixture is too lean when cold; the percentage or operating time for the relevant temperature at start-up must be increased. If the engine is hot, the causes could be: – Candles – Reels – Defective injector(s) – Lack of valve sealing – Air intake |
(2.0 Wifi) When I'm connected to the device with my app, other apps stop working (Android).
| Switch the apps that are blocking to 4G or 5G | Go to Settings / Connections / Data usage / Apps using mobile data / select the apps you want to use without relying on Wi-Fi |
(2.0 Wifi) I just installed the app on my smartphone, entered the Wi-Fi password in my settings, and the app is stuck on the login page.
| You must wait 5 minutes | The very first time you connect after installing the app and entering the Wi-Fi password in your smartphone's settings, the app won't start immediately and will remain stuck on the login page as if you weren't connected. Because it's a Wi-Fi connection without an internet connection, your smartphone will need approximately 5 minutes to accept the connection. Once this first connection is accepted, you won't have this problem again; your smartphone will have saved this connection and will automatically connect to the device. |