whiteLS1

iTrader: (15)

About a month ago I bought 96 Z28 M6 102k on it. The car has had a high idle and smells like it is running rich.

So I went to work to start trying to figure out what was going on. Pulled the codes got a P0420,P0430, and the IAC code(forgot the #). I removed the throttle body cleaned it and the IAC. During that I found the rubber elbow was torn so I ordered the Jegs elbow. Once I installed that and clean Throttle body and IAC the IAC code went away. Still have the P0420 and P0430. Im not to worried about those bc I know the Cats need to be removed.

But now I have P0171 and P0174 Intermittent. Still have a high idle 1200-1300rpms.

I have change PCV valve checked everything for vacuum leaks (sprayed starter fluid in multiple locations) inspected the MAF looks super clean.

Car runs great. The high idle and P0171/P0174 are bothering the crap out of me. Anyone have any ideas. Or is my only choice hooking it up to a scanner... And if that's what needs to be done is there anyone near Plant city that can help me out Im willing to pay. I just need someone who knows lt1s not a random shop.

thanks for the help
Matt

Octavarium

iTrader: (4)

The P0171 and P0174 are lean codes so I doubt you are running rich and instead are running lean, which would indicate you have un-metered air getting into the engine somehow and this would cause the high idle issue. I would double check all of your vacuum lines and intake again to make sure you do not have a vacuum leak.

If that fails, I would check that the set screw in the throttle body isn't screwed in to the point where it is keeping the throttle blades propped slightly open. This is an unlikely culprit and it wouldn't solve the lean issue but its easy enough to check.

whiteLS1

iTrader: (15)

I can't seem to find a vacuum leak anywhere. With the intake elbow off the throttle body blades appear to me they are closed all the way. Idk I'm lost.

myltwon

iTrader: (1)

if you have a high idle after throwing a IAC related code, you might need to "reset" the IAC using a special procedure. I forget it off the top of my head but more or less involves restarting the car a few times with the gas pedal depressed and forcing the IAC to relearn its proper position.

Search on here for IAC reset for more info.

whiteLS1

iTrader: (15)

IAC fixed high idle. No new codes yet. Probably going to need a few more drive cycles to see how everything else goes