so I didn't want to just post another high idle thread. I just havent read anyone describe my symptoms. 9/10 my high idle (2000-2500) goes away when I turn off the ac. Also since it's a 5 speed, if I'm cruising, I can kill the ignition and turn it back on. This seems to ease things temporarily as well. ( probably not marvelous for things, educate me) Now just today, I took my dipstick out right after someone turned it off and there was serious vacuum from the crankcase. If I'm not mistaken, there is supposed to be a crossflow to evaporate gasses? There was definitely no flow happening besides from my dipstick hole. ( at that moment). I think there has to be link between my ac, my high idle, and crankcase vacuum. For those who doubt, the vacuum of the case was absolutely equal to my engine vacuum. Egr stuck? If I knew where to start, I wouldn't be posting. Thanks all.

 

So this all started very manageable. Didn't happen very often. Now it's quite predictable. "Max" ac/ recirculator seems to be the culprit. If I start the truck with max ac on, there are no issues. However, if I get way into the throttle, my high idle issue sticks with me until I shut it off and restart. I don't know enough of how all the vacuum ports interact to guess what's wrong. Could a tired smog pump be an issue? My motor is rebuilt and I was told it had a lot of those things replaced. It never gave me any problems till recently so clearly it's something gone wrong instead of improper reassembly.

 

Crankcase vacuum sounds like the pcv valve is stuck open...which would also cause high idle. Try a new one...they're not very much.

 

Try this first... next time it's high idling, pull the plug on the IAC (Idle Air Control) actuator. If it idles way down or stalls then it's a control problem. If it continues then yeah you have a mechanical problem like sticking throttle or vacuum leak.

 

Thanks guys. will keep everyone updated with the fix or new symptoms. Lots of high idlers around here huh?