my 2002 Chevy Tracker has run faithfully for the last 5-6 years. a few things have come up recently that have needed to be replaced, but nothing huge. after my AC compressor was replaced, my car started powering off in the middle of driving (not while revving engine standing still). mostly on cold starts, but now more frequently. mechanic swears it has nothing to do with AC compr. but he is checking drive train today. He has changed the tranny fluid, fuel filter, cleaned the gas tank, cleaned the throttle body (IAC motor), cleaned the mass airflow filter sensor, checked the battery voltage in case of an alternator problem. he has scanned the vehicle while driving and sitting still several times and no codes come up. any one have any idea???
Work on the AC compressor would have involved the area where your crankshaft position sensor is located, and a problem with that can cause these kinds of symptoms - even without setting any error codes. The mechanic should inspect the wiring, sensor & connector to the sensor. At the very last a good cleaning & reseating of the connector would be wise.
I wanted to comment about the “decompressor” but decided not to.
cigroller - mechanic is going to try replacing the sensor now. he has checked the wiring, but hopefully will again after i talked with him about it. you are right about the symptoms: the motor was shaking, and hesitating on acceleration as well. it also pulls slightly left when it powers off. not sure if that adds a piece to the puzzle. i’ll see what this next step does and might be asking again! (but crossing my fingers it will work)