AIC questions
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
IAC questions
Just wondering what the IAC is supposed to be reading when hooked up to a diagnostic scanner. It is reading 144 consitantly. Mech said that is way high, should be around 40-50. I am wondering if the IAC is bad or is there something else that could be causing it like loose or broken connection.
[Modified by hz900, 11:50 AM 9/24/2002]
[Modified by hz900, 11:54 AM 9/24/2002]
[Modified by hz900, 11:50 AM 9/24/2002]
[Modified by hz900, 11:54 AM 9/24/2002]
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: AIC questions (hz900)
The Idle Air Contorl (IAC) is a servo not a sensor, so the ECM shows how many steps it is commanding the IAC pintel to move.
That high value means that the ECM is trying to reduce air flow at idle.
Possible causes are:
-carbon buildup in the TB that holds the throttle plates open slightly.
-carbon in the IAC's pintel bore under the TB preventing it from moving as commanded.
-a vacuum leak allowing excess air into the intake.
-the IAC connector or wiring could be defective.
-the IAC may be defective and need to be replaced.
That high value means that the ECM is trying to reduce air flow at idle.
Possible causes are:
-carbon buildup in the TB that holds the throttle plates open slightly.
-carbon in the IAC's pintel bore under the TB preventing it from moving as commanded.
-a vacuum leak allowing excess air into the intake.
-the IAC connector or wiring could be defective.
-the IAC may be defective and need to be replaced.
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
Re: AIC questions (65Z01)
Thanks that brings me back to my original problem of a vacuum leak somewhere. That must be a hell of a leak to make the car act this bad. According to the sniffer it has a leak somewhere underneath the plenum near the TB but can't tell where from looking. Guess we'll have to tear it back down and see what I missed or screwed up.
