I did a load of maintenance on the wifemobile about three months ago - new front seals, timing belt and tensioner, belts, radiator, hoses, water pump, etc. Car ran great. About two weeks ago the idle shot up to about 1600 and stayed there. I cleaned the throttle body and there was no change. I tried adjusting the knurled idle adjustment screw and it had no effect - except to increase idle when it was screwed waaaaaay out. I also completely disassembled the knurled nut/housing and cleaned it out. (Yes - I realize I probably hosed the adjustment - I'll worry about that later) I checked the adjustment of the TPS per the FAQ and it seems fine. Put it all back together and still a solid 1600 idle. I did notice that when you give it gas and let off, the idle starts to drop below 1600 - maybe down to about 1000, and almost seems like it catches itself and bounces back up to 1600. I figured the extra air had to be coming from somewhere and I couldn't find any vacuum leaks so I partially clamped off the hose from the main air intake pipe to the idle air control valve. Now it idles great. My question is: have I just determined that the idle air valve is bad, or is there something else driving it that may be the problem. What's my next step.

And while I'm posting, I have a stock Volvo AM/FM/Cassette deck with speakers in the dash and the rear doors. I have cutouts and wiring for speakers in the front doors, but I get no sound when I plug speakers into these wires. What gives?

As always, thanks for your help.