He works in mysterious ways.

Don't bother with checking underneath the hood. Bill Marlowe, Chip Daniels, Seth Tucker and Cougar Cash cause the "Fast Idle" and it has nothing to do with your car.

I've got two idle-adjusting screws, and although one is for idle-up, it appears to only move the idle up a little when the fan, AC etc. are running. There's no indication that this is also controls ...