Originally Posted by
Oggie79
First week it worked fine and no problems,and sudden the car would not start,took the chip out and everything was ok again. I waited a week or so and tryed the chip agian, car started and was running 500 O/min, after a few minutes it was running normal 1000 O/min, after about 30min of driving something happened, the car did not run normal at all, seemed like it got to much fuel or something so i had to take the chip out again.
Regards
The EEC is self learning. It relies on the HEGO to learn the closed loop fueling needs of the engine and stores the results in KAM. 30 min is enough time. As it runs worse after 30 min rather than better, that points to a sensor issue, possibly the HEGO. Get a known good wideband on it and compare to HEGO output. Give your MAF a good clean. Check the ECT sensor. What do the plugs look like, should give you a pointer to rich or lean.