You may have a bad IAC ( idle air control) but try eliminating any vacuum leaks and 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. Also check to make sure there are no air leaks in the tubing connected to the IAC. If it still has a problem, replace the IAC.

Answered by Wrenchtech (expert)
14,743 answers provided