Mechanics

GMC SUBURBAN ENGINE PROBLEM

1994 GMC Suburban • 275,000 miles

My 1994 1500 two wheel drive suburan engine rpms surges, rpms drop then rises back and fourth until engine dies. What could cause this? It was running well last 30 days getting worse
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Hime1
December 31, 2012.




First eliminate all vacuum or air leaks in the system. You may have a bad IAC ( idle air control) but try cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.

Wrenchtech
Dec 31, 2012.


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