Car runs fine, but idle is low/erratic (500-700) before the engine has warmed up or when a/c is engaged (a/c works great, though). Once car is warm, idle is stable (about 900). Low ambient temperatures make this worse, not surprisingly

I have tried adjusting the black plastic knob on the throttle body; that just raises or lowers all the numbers I gave above by the same amount across the board.

Does this sound like the Ide Control Valve (also called Idle Stabilization Valve) is bad?

Plugs/cap/rotor/wires all fine.

The only other related detail I can think of is that the a/c compressor groans sometimes when its engaged, but I repeat that it works just fine (blows cold).

- Dan
care for: 86 744, 88 245, 90 244, 96 965