IAC Valve replacement
Thread Starter
Safety Car
Joined: Dec 2001
Posts: 4,472
Likes: 0
IAC Valve replacement
Anyone have a guide or the steps to replacing the IAC on a '91 L98? I have observed it once so have a pretty good idea but I would like to have some instructions or something to follow to make sure I get all the correct bolts.
I have the Haynes manual but haven't been able to find anything in there to get me going in the right direction and a google search of the web hasn't helped much, either.
Thanks.
I have the Haynes manual but haven't been able to find anything in there to get me going in the right direction and a google search of the web hasn't helped much, either.
Thanks.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
With ignition Off disconnect the harness from the IAC connector and remove the IAC.
Clean the bore in the IAC housing under the TB with TB cleaner. You should also clean the TB bore & blades at this time.
Install the IAC, per directions supplied with the unit and connect the wiring harness.
Start the engine and check idle. If idle speed doesn't settle to 600-700rpm in Park use the method on my site to set base idle.
Clean the bore in the IAC housing under the TB with TB cleaner. You should also clean the TB bore & blades at this time.
Install the IAC, per directions supplied with the unit and connect the wiring harness.
Start the engine and check idle. If idle speed doesn't settle to 600-700rpm in Park use the method on my site to set base idle.
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by Square
If you can remove your IAC with the throttle body on, then the above post is way easier than what I originally had typed!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
And don't forget to retract the pintle, as per the factory (Helms) manual, before you reinstall it. You COULD damage the pintle, pintle seat, the IAC motor itself, or all the above.
EACE ON!!!
EACE ON!!!
Race Director
Joined: Jan 2004
Posts: 18,727
Likes: 711
From: Bergen County, NJ
Originally Posted by dgoodhue
I would get new gaskets, lower TB and IAC gasket while you at it. Also, pull apart and really clean the IAC passage below the TB.
Thats what I did, also did the TB bypass.
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