Okay, here's where I'm at on this low idle thing. Since I've adjusted the throttle plate, switch etc. per the Volvo book, she runs great. Off idle response is greatly improved, idle however, is still low at 650. Remeber its 650 with or without AC and with or without electric fan running. Apparently idle control valve is working OK. Checked for vacuum leaks as suggested, found a cracked vacuum hose at the MAP sensor, replaced it and got a very slight improvement. No other cracks/leaks found, still need to get at some line that goes under the air box to the charcoal canister.

Marked crank pulley to see if it shifts, haven't driven it enough to make a call there, yet. Since these MAP sensors can act erratically, thought I'd replace it for at least some insurance. I'll call the dealer Monday, but it's just a GM part. I tried a GM dealer, no luck and a couple of auto parts places, no luck. There does not seem to be a listing for this piece under Volvo, though both places recognized the part and said it was about 40 bucks.

Anyone got a GM, NAPA, Borg Warner or other reputable brand part number for this GM MAP sensor that might be giving me headaches? As always thanks for your help.

Mike