In Reply to: 88' M5 with idle troble posted by Curt K. on November 21, 1999 at 05:01:16:
I had a similar problem with my car. I found a note from Jim Conforti about setting the idle on an S38 motor, followed the steps, and the problem disappeared. Here are his instructions (paraphrased).
1. Warm car, CO/fuel mix readings taken and validated; adjusted to spec if necessary.
2. Shut off car.
3. Remove plug from IDLE CONTROL SWITCH (not VALVE..SWITCH!!)
4. Bridge all three terminals of switch.
5. Restart car.
6. Set BASE IDLE using large throttle bypass screw near valve cover.
7. Recheck idle CO.
8. Shut off car.
9. Reconnect idle control switch.
10. Enjoy proper idle.