Chuck is right about the stalling problem driving you crazy. I have the same exact problem on my '88 260e and recently replaced the airflow sensor pot. The car ran fine for a couple weeks then one night started stalling again. Every time I would come to a stop the lights came on the dash and I had to restart it. Besides the intermittent stalling, the car runs and idles smooth as silk.
I cleaned the idle control valve and tested the decel switch (through about 100 cycles) and both seem to be okay.I had ruled out the fuel pump and pump relay as the cause because the problem only occurs when at idle or coming to a stop - never while driving. I would think a fuel pump problem could occur at any speed. Or am I wrong?