I have a 93 Chevy van with 97000 miles and a 5 liter engine. Recently the check engine light came on with trouble code 35: "Idle Air control system". I replaced the valve, reset the computer and the same code comes on again (usually when pulling over and idling after driving on the highway). I am stumped. Can anyone figure out what the problem could be? I checked the vehicle speed sensor and it's fine. One possible clue is that the cruise control also stopped working. Also, the engine always surges for a while before idling at the proper speed (like when braking for a red light). These two clues may be completely unrelated. Any help is very much appreciated. Karo: m snipped-for-privacy@hotmail.com
Chevy van, tr.code35. See if you can solve this 1
Mar 27, 2005
2 Replies
Vacuum leak can cause both problems. Look around the TBI unit for a split vac. line or one that fell off. Also look at the lines that run up to the cruise unit since one of those could also be the culprit.
Is this a Throttle body engine or the vortec engine ? have seen where the egr valve get dirty under the pintle and keeps it open a weee bit , cause slight rough idle and surging ....mostly on the votec engine , also a vacuum leak can cause it too....might have to hook it up to a scan tool
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