I would like to thank you for your time and helpful answers. My daughter bought this car without me checking it out first. Seems these cars came from the factory with alot of problems,(electronics,brakes,trans,etc.) So,thanks again and have a good one!
engine revving up on 1992 Mitsubishi Diamante
by waynea40 in White Bluff, TN on January 22, 2010
ANSWER by Bret Bodas on January 22, 2010
Good luck, let us know how it all works out with your daughters Diamante.
ANSWER by Visitor on July 08, 2010
As you said,these cars have a history of electronic issues.I have a 92 and love it,learned to live with the quirks.I had a similar issue,engine rev.The fix was common,and easy,replace the idle air controller (sometimes called IAC,ISC or stepper motor).It requires loosening the intake air hose and moving it out of the way to access the iac on the rear bottom of the throttle body.Remove the wiring plug and then the two screws (10mm I think)that hold it in place.One can be seen and one can't but you can easily feel it,and replace/reverse procedure.Make sure "o" ring is in place.Then start car and let it sit idling for about ten minutes so it can communicate/update with the cars computer. You can find IAC at salvage yards/parts recyclers or buy one online from hundreds of places including ebay.
whats causing my engine to rev up to 2200-2300 rpm for no apparent reason? still does it if i shut engine off and restart. then it will go back to normal,about 7to800 rpm.
checked vacuum lines,they seem ok. check engine lite is not on,but the coolant lite is. coolant is full in radiator and the reservoir. started black smoking, bad egr maybe?