my '92 300E i6 has started to act up . Hard start and acts like the timing is retarded, then starts and runs fine. Sometimes the throttle needs a soft touch or it stalls. My guess is a sensor but I don't know where to hunt for one..

replaced both water temp sending units on the head. Car starts and runs fine till it gets to operating temp, then it stalls and backfires. It is not running hot, water level is fine, lower and upper hoes are hot so it isn't a sticky thermostat. I'm stumped.