Fast Idle Problem

[VaGent]

OK guys I need some help. I took the TB & IAC on my 2.9 & cleaned it really good. I installed new gaskets when I put them back. The engine runs 100% better then it did BUT, I cannot figure out why it won't idle below 1200 RPMS after cleaning these items. I've checked every hose I can find that is a vaccum hose, checked the timing, made sure the STOP screw on the throttle body was not turned in too far, rechecked the TPS have done everything I know to do. It was idleing at 850-900 BEFORE I cleaned the TB& IAC valve & that is all I did to the engine other then check out the vlave cover gaskets. I'm at wit's end trying to figure this one out. I even checked the timing & it was set @ 10 degrees just like the book called for. Anyone got any ideas what the problem could be? I'd sure appreciate some help on this.

 

[mhughes165]

sounds like a vaccum leak to me, do the carb cleaner methoud, or starting fluid, and spray it around and see if the truck surges anywhere.

 

[IMenriched]

sounds like a vaccum leak to me, do the carb cleaner methoud, or starting fluid, and spray it around and see if the truck surges anywhere.

+1...with check for vacuum leaks.

it may still be the AIC, even thou you've cleaned it. try cleaning it again. if that doesn't do it then you may need a new one. or maybe borrow one that is working well and try it.

 

[VaGent]

Thanks for the info guys. I found it using the spray method using carb cleaner. Had a vaccum hose that was cracked going to the IAC itself. I felt like it was a vaccum leak all along but wasn't able to find it until you guys reminded me about using the spray method. Two heads are always better then one. Thanks again.