Hi, I have a 1990 525i. Just recently, I have been working on the stereo system. My dad and I have been disconnecting the battery, for safety reasons when working on it. We always disconnect the red, or positive cable from the battery.
My problem is, everytime I disconnect the battery, then reconnect it after I am done working on it, and start my car up, it idles funny and the engine dies at times. The car will idle at very low RPM's, and even die at times when I put in the clutch or am in neutral and slowing to a stop. This will go on for a while, 2 or 3 days, then it goes away. I have brought my car to a BMW mechanic, and they have run a full diagnostic test on it, and found nothing wrong. The only thing they did not test, was the "brain" of the car, the CDM, or something like that.
I wanted to know if anyone knows what the problem might be, and or how to solve it. I would appreciate any help. Thanks