Mechanics

COLD WEATHER ENGINE SURGE WHEN WARMING UP

2002 GMC Yukon • V8 4WD Automatic • 125,000 miles

I have a 5.3L GMC Yukon that surges terribly while warming up. The engine revs up to 2000 rpm then drops to below 900rpm, sometimes dying. It continually does this until it warms up, then it idles pretty smooth at about 800 to 900 rpm. Sometimes I have to keep the working the accelerator pedal to maintain about 2000 rpm till warm up. Can you advise me as to the solution to my problem? Thanks
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Kenneth Craig
November 28, 2010.




Hi
Maybe IAC and/or ECT. Clean IAC and throttle bpody with approved cleaner. OHM check ECT should be @1800 ohms cold going down as engine warms. See diagram for locations


Docfixit
Nov 28, 2010.


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