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Topic: Excessively high idle

in Forum: C4 Fuel, Emission Control, and Exhaust Systems


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Excessively high idle (1/6)
 8/22/22 7:06am
firstvette84
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Joined: 11/5/2013
Posts: 7

I have 1984 C4 with Crossfire.  My idle was rolling and kept stalling at lights. I changed the IAC valves after doing some research. Now I cannot get the idle back down to normal. When cover the air holes where IAC valves are I can bring the idle down to about 1000 rpms in neutral otherwise I am at 2600.

Any suggestions?

Thank you

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Re: Excessively high idle (2/6)
 8/22/22 9:15am
Adams' Apple
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Duncanville, TX - USA

Vette(s):
1985 Coupe-L98/Auto,Bright Red/Carmine. 1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.


Joined: 3/18/2009
Posts: 2201

The IAC valves need to be "relearned". There is a procedure for this that requires a specific tool to block the valve(s) while doing it. I have the info at home I can send this evening if you want.



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Re: Excessively high idle (3/6)
 8/22/22 9:23am
firstvette84
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Yes. Thanks. That would help

Re: Excessively high idle (4/6)
 8/23/22 5:16am
Adams' Apple
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Duncanville, TX - USA

Vette(s):
1985 Coupe-L98/Auto,Bright Red/Carmine. 1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.


Joined: 3/18/2009
Posts: 2201

From the service manual...



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Joel Adams  
My Link

 
   
(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Re: Excessively high idle (5/6)
 8/23/22 9:07am
firstvette84
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Posts: 7

Thanks. I will give it a try

Re: Excessively high idle (6/6)
 8/24/22 9:57am
TLAVAC
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beaufort, SC - USA

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1990 Turquoise Corvette (his) & 1990 Turquoise Corvette (hers)indy festiville car for sale


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Replace the idle air control valve under the throttle body

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