My 745ti (86') is idling at 2500rpm. It was idling at 1500rpm(still too high), so I cleaned the idle control valve out with carb cleaner. Now, at 2500, nothing I do will bring it down. Is my idle control valve shot?

check the throtle body, clean it. Adjust the TPS switch.

If it's idling at 2500, your idle air motor is not shot.

How's the wiring harness?

I just replaced the wiring harness, got it from Dave Barton. How do you adjust the tps switch? Is that the little black box on the side of the throttle body that is supposed to click as soon as you open the throttle?

Don't mean to question your Volvo knowledge but just covering bases..Are you sure TPS and Idle control were not interchanged?? This is very common (I did two wiring harness replacement this year, '86 744 & 85 744T..both harnesses from
Dave B.)..Next check wiring colors...TPS orange,Brown,Red & white..Idle control
..Green&Red,Green,yellow & red.Now, that is the color sequence on my 86 744GLE I don't know if the same holds true for the turbo.I had your problem early this year and it turned out that my wiring harness (replacement) connector pin were in a different order..Check the color coding sequence on your old harness and update us..Good luck!!
--
ReySC.. '86 744 GLE (Daily Driver),94 944T.. http://groups.msn.com/Reysc/myvolvophotoalbum.msnw?Page=1

Thats a darn good suggestion. I'll check and get back to you. Thanks for all the help, I appreciate it - I don't know what I'd do without this website. I've only had volvos for two years now, and I'll never drive anything else!!
86' 745ti(334,000), 83' 240(373,000), 91' 240(362,000)and they all run!!!.