Help!!!!
Thread Starter
11 Second Club
Joined: Aug 2004
Posts: 891
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From: minneapolis,mn
Help!!!! I keep having problems with IAC valves sticking. Is this a tuning issue or what is going on. I am on my third IAC valve now they either stick shut or open any ideas would be appreciated.
Depends. It could be a tuning issue, but you would need to log your long term/short term idle trims to find out. If the PCM is commanding it to stay open/shut, then you need to adjust the Desired Airflow table in your tune.
Thread Starter
11 Second Club
Joined: Aug 2004
Posts: 891
Likes: 0
From: minneapolis,mn
I switched back to my old IAC and now I have a zero IAC count. So I'm guessing it's stuck shut. So It's not adjusting the idle at all. But the new one I had in it was making it idle at 3500 rpm's. I've been having my tuning done at a local shop[ I'd guess it's not the tune but not sure what it would be. I have ls1 scan and it sucks so I cannot log IAC counts with it.
I take that back....the whole desired airflow deal is the second part of the process. To get the car to idle after installing a cam, the throttle body needs to be drilled or the set screw needs to be adjusted to allow more airflow, right? If your IAC is closed (sitting at 0 steps), it means the motor is getting more air than it thinks it needs. Therefore, you either need to close the tb blade off by readjusting the set screw down (or changing the ETC table in the tune for cars with drive-by-wire) or buy a new tb because they may have drilled too big of a hole in the blade. Ideally, this works in parallel with the idle trims. You want them to remain close to 0 while the IAC steps stay close to ~70 at a warm idle. If any of this doesn't make sense to your tuner, I'd suggest you find a new one.
