· Founding Member
If the EGR passage is clear (most higher mileage mk2s are completely plugged with soot), then a valve thats not closing all the way at full throttle could reduce performance. But that doesn't jive with the problem only appearing when the car is restarted warm. O2 sensor provides feedback only in steady state operation, not when accelerating so thats not it either. Sounds to me like your car is going into warm-up mode when the car is started regardless of the engine temperature. A too rich mixture or too far advanced timing when the engine is already warm would reduce performance. Test the cold start injector time switch and the temp sending unit with a multimeter as in the TSRM. Perhaps someone could post the link to the online manual if you don't have your own copy. Good luck.