'89 325is (The 535i working really good these days.)

Bentley has mucho info on bad idle problems. And what formerly was an intermittent condition has progressed to a very solid "won't idle worth a crap" situation. This is gratifying, because now I can have a good shot at fixing it.

Bentley says somewhere to remove the harness connector from the ICV while it's idling, and the idle speed should increase to 2K. Mine doesn't change much at all, and I have to keep my hand on the throttle to keep it running reliably. They also say I should hear humming and clicking from the ICV, but I can't discern any sound or feel any vibration.

So, as soon as I have time, I will perform the electrical checks of the idle/full throttle switch and the ICV, and the coolant temp sensor (If I can get the harness connector off- the fuel rail is in the way).