About Josh Fields Expertise I can answer questions related to the BMW e30. These are the cars produced from 1984-1991 (1992 for convertable) in the United states. I am more fluent with the six cylinder models, although few things changed for the 4 cylinder cars. I know most of the problematic areas of these cars, and have found ways to fix them.
Experience I have owned six different E30's over the last 10 years. I do all my own work, and know about ever nut and bolt on these cars.
Question I know you mostly work with e30s but think this problem may be a general one. I have a 90 535i and upon starting the vehicle after it has been sitting for over an hour or so, the car will idle pretty rough. It will not stall out ,but after about 30 sec to a min the idling will become smooth and will run fine. If I try to drive before this it will really struggle. Any ideas?
Answer Jim,
You are right, I mostly work with E30's, and most of my experience is with them and their engines. Your car has the "big six" engine called the M30. I have very little experience with this engine and its electronics.
However, your problem could be that the engine is in need of a tune up, or the cold start injector is not functioning properly. This would explain why the engine runs rough when cold. Test the cold start injector to see if its getting voltage, if it is, then pull it out and make sure the injector is squirting fuel.
