possably throttle plate problem ..vacum leak ....is it setting any codes >? ecm could have went south
make sure there is not a idle releard for this model too
bg
April 2009
I can answer this question...
i have a 92 chevy 1500 350 and it idles high i replace tps and the iac valv?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.