My 89 Vandura 5.7 lit. idle's so high that when I put it into gear it slams pretty hard into gear. Anyone know how to adjust the idle or whatever I need to do to fix the problem?
Idles high and I can't find any kind of an adjustment screw or anything to adjust. anyone
have any ideas?
Vacuum leak. Unmetered air entering throttle body will cause high idle. There is no adjustment. Or I don't know if a 1989 has a TPS, Throttle Position sensor, it probably does. The butterfly in the throttle body may not be closing all the way. Listen for a sucking sound, or hoses off, or nipples with nothing attached, all will cause a vacuum leak
Search GMC Vandura Questions
GMC Vandura Experts
Related Models For Sale