Been a while since I cleaned the IAC on my 1991 745T, but the little door in there **IS** supposed to move if I push gently on it with a screwdriver, isn't it?

If the answer is "yes," then I think I have found the problems with the idle surging and poor driving.

I'm pretty sure that the little door, which operates like a revolving door, did move the last time I cleaned it. It is frozen in place now.

Now, if someone in town has one in stock and will charge me an arm and a leg for one. Heck, if the price is right, I'll even consider buying it from Volvo.
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Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)

If yours is the 3 wire, you can test it. Put 12volts to center pin and ground out either side and the valve should slam shut. Tried any electrical contact cleaning yet?
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Post Back. That's whats makes this forum work.

Well, it looks like I was trying to turn the IAC the wrong way. It works just fine, even snaps open when I apply 12V. It is the two wire type and seems to work just fine. That means my problems are elsewhere.
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Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)

Gretings,

Next thing you could check is the throttle position switch and it's connector.
I had the surging, crappy idle symptoms and the connector was only connecting about half the time.

If the TPS doesn't tell the computer the throttle is closed then apparently the idle control circuit doesn't work. Might be a bad TPS, have had a couple that clicked when adjusted properly but the switch wasn't completing the electrical connection.

Hope this helps. rcs