Having problems with your 1989 GMC Suburban ?
I have a problem with my1989 gmc suburban, the idle is set way too high ( apx 2700 rpm) where is the idle adjustment screw located on the carb?
There is no carb, and no adjustment. if it idles too high, there is a vacuum leak, so check the large hose going from the base of the throttle body to the valve cover. if thats OK, these are known to have a leak at the base gasket, usually at the rear of the throttle body. spray carb cleaner around the base and see if the idle changes, if it does, replace the base gasket.
Repair Help & Product Troubleshooting for 1989 GMC Suburban
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