While trying to figure out what the hell is causing my high idle after a cam swap. I took apart the TB and cleaned out the IAC valve and the butterflys. I could NOT believe how much crap was in the coolant passage underneath the TB. It literally looked like marbles and mud in there! So I just bypassed the throttle body altogether.

After cleaning the IAC I start up the car and it idles at 1500rpms and will sit there for a while before going back to 1100-1200rpms. Im following the stock tach and my PCM was set to idle at 950. Im thinking my high idle is whats eating up the lope on my CC Xtreme 236/242 ground on a 110lsa.

How does one look/test for vaccum leaks?

-B

 

Get yourself some carb cleaner and spray it around the intake. When the idle goes up then you know where the leak is.

 

if you sprayed carb cleaner down inside the IAC that could be some of your problems also. Does the car do it when you drive it down the road then stop??

 

I took everything apart on the TB and cleaned it out so Im not sure it that makes a difference.......and it'll hang at 1,500rpms at every stop or anytime I take my foot off the gas.

-B

 

and then slowly works it's way down right !!! if so you got carb cleaner down inside the IAC you'll need to replace it. If you had a leak it would stay a 1,500 and not slowly come down, because the IAC couldn't adjust for it.

 

Phil, have you solved this problem by replacing the IAC? Becuase mine will go up and then come down, fluxuates when I come to a stop. Or is this just speculation about the IAC? I know, I've gotten carb spray in it, but this drives me crazy too, I haven't checked for all hoses and don't think I have a leak. I will do it some days and not others though