Haven't really touched the car in the past 3/4 months. I need to check/change the oil, sunroof started to leak a bit from the panel. I gotta buy that seal kit and slap some on, hopefully that solves it. Roads are... constantly some sort of wet and i am on winter rubber, i have not revved the car past 3k in 3/4 months. Drives fine. I have a few things to do some spring time: install spulen catch can, h&r sway, buy shocks and change suspension, and figure out cyl 3 misfire. I asked ChatGP
Why do I have a cylinder 3 misfire in my mk7 gti. I have an upgraded turbo, i replaced the plugs with colder plugs.
A "cylinder 3 misfire" in a Volkswagen GTI with an upgraded turbo could have several possible causes. Some common causes of misfires include issues with the spark plugs or ignition coils, a problem with the fuel injector for that cylinder, or a vacuum leak in the intake system.
It's possible that the colder spark plugs you installed may not be the correct heat range for your engine, which can cause misfires. It's also possible that the upgrade turbo caused more pressure and cause more heat, this can cause the spark plugs to burn off faster than normal.
Another possibility is that the ignition coil for cylinder 3 has failed. It's also possible that the fuel injector for that cylinder is clogged or not functioning correctly.
A vacuum leak in the intake system can also cause a misfire. Vacuum leaks can be caused by a number of things, such as a cracked or loose hose or a failed vacuum actuator.
It's recommended to perform a diagnostic check with a OBD scanner to determine the exact cause of the misfire, and then address the problem accordingly.
Thank you. I replaced the injector already, as well as the ignition coil, but i have not checked the intake system. Do you think it could be related to the engine speed sensor
It's possible that the issue could be related to the engine speed sensor (also known as a crankshaft position sensor or CKP sensor). The CKP sensor sends signals to the engine control module (ECM) about the position and speed of the crankshaft, which the ECM uses to control the ignition timing and fuel injection. If the CKP sensor is not working correctly, it can cause a misfire in one or more cylinders.
It's also possible that the problem could be caused by a faulty camshaft position sensor, which works in conjunction with the CKP sensor to control the timing of the engine.
Given that you've already replaced the injector and ignition coil, I would recommend checking the intake system for vacuum leaks and also checking the engine speed sensor to see if it's working correctly. If the problem persists, it would be best to consult a professional mechanic or dealership for further diagnosis.
the misfire happens every time at 6700 rpm
If the misfire in your GTI only happens at a specific RPM, such as 6700 RPM, it could indicate an issue with the engine's ignition or fuel system. Some possible causes for this could include:
- Ignition timing: If the ignition timing is not set correctly for your engine, it can cause a misfire at high RPMs.
- Fuel pressure: If the fuel pressure is not correct, it can cause a misfire at high RPMs.
- Air/fuel ratio: If the air/fuel ratio is not correct, it can cause a misfire at high RPMs.
- Exhaust: If the exhaust system is not functioning properly, it can cause a misfire at high RPMs.
It is also possible that this issue is caused by a problem with the engine control module (ECM), which controls the engine's ignition and fuel systems. A malfunctioning ECM could cause a misfire at specific RPMs.
It is recommended to check the engine's ignition and fuel system, as well as the exhaust system. Also, it is recommended to check the engine control module for any malfunction or error codes that may be causing the problem. It might be best to consult a professional mechanic or dealership for further diagnosis.
i had the car professionally tuned to accomodate all the modifications
If your car has been professionally tuned to accommodate the upgraded turbo and other modifications, it is likely that the cause of the misfire at 6700 RPM could be related to the tuning itself.
A professional tuner should have done a thorough check on the engine, including the ignition and fuel system, as well as the exhaust system, and made any necessary adjustments to ensure optimal performance and to prevent issues like misfires.
It's possible that the tuner may have overlooked something or that there was an issue with the tuning process. It's possible that the tuner did not adjust the air/fuel ratio, or that the ignition timing is not set correctly, which can cause the misfire at high RPMs.
It's recommended to contact the tuner who worked on the car and explain the issue you're experiencing. They should be able to provide a solution or further diagnosis.
Keep in mind that if the car was tuned for high performance, it's expected to have some issues with the engine, it's important to check the engine's performance regularly and have it serviced by a professional.