Okay, don't shoot me, if you have heard me on this subject ten times before, but I am continue to be mystified by the fact that my 745 Turbo (1991) idles at between 550 and 650 when fully warmed up (that is what the onboard tach says, on the dash board). I have done all of the obvious things, believe me - IAC, checked AMM, new TPS, adjusted it precisely, throttle body cleaned to within a millimeter of its life, RPM sensor, fuel pressure sensor, ECT sensor, and a few I haven't mentioned. None of the obvious things have affected the idel AT ALL. I even found a used ECU from a guy on ebay to see if that might be the problem and it made not a hint of difference (both ECU's are probably fine). Broke down and went to Keeler Volvo here in Albany to see if they could diagnose it and they didn't even pay attention to it as a problem, so maybe I need to just forget about it and get a life!

Thanks for listening and for your patience with my struggle with the low idle problem. I even had someone bring this up at the local VCOA chapter meeting to see if anyone had any insight, and nada! Any ideas???
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Darius in Albany NY '86 744 GLE (175K, given to my mother-in-law); '91 745 Turbo (167K-my 'Little Red Wagon')