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

theres a temp sensor under the 2-3rd injetor on the head, check that one out its inexpensive and can cause inaccurate readings to the computer and cause that problem, make note when you look at the right side of the block its the second one back ( youll see what i mean ).