Possible Bad IAC?
07-27-2015, 04:34 PM
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Location: Cary, NC
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Car: 87 IROC
Engine: 420 EFI
Transmission: TKO500
Axle/Gears: Moser 9" 3:50
Possible Bad IAC?
Hi Guys,
I think I have a bad IAC? Would like to get your opinion.
Two weeks ago, the car ran fine from cold start through hot shut-down. The RPM control was ok.
Last weekend, the car cold-started but the RPM's never hit the programmed value. The idle RPM was below the cold-start set-point. This idle RPM error also existed when hot.
The idle RPM is around 750 (cold or hot) which is too low for my engine combination. Engine idle is programmed for a 900 RPM idle.
The sensors seem OK. No DTC are flagged. With the key set to run mode, I hear the IAC running.
I am thinking something mechanical has happened to the valve?
I will check the wiring from the ECM to the IAC.
Any other possibilities?
Best Regards,
Bruce
I think I have a bad IAC? Would like to get your opinion.
Two weeks ago, the car ran fine from cold start through hot shut-down. The RPM control was ok.
Last weekend, the car cold-started but the RPM's never hit the programmed value. The idle RPM was below the cold-start set-point. This idle RPM error also existed when hot.
The idle RPM is around 750 (cold or hot) which is too low for my engine combination. Engine idle is programmed for a 900 RPM idle.
The sensors seem OK. No DTC are flagged. With the key set to run mode, I hear the IAC running.
I am thinking something mechanical has happened to the valve?
I will check the wiring from the ECM to the IAC.
Any other possibilities?
Best Regards,
Bruce
08-01-2015, 11:26 AM
#2
Member
Thread Starter
Join Date: Jul 2006
Location: Cary, NC
Posts: 212
Likes: 0
Received 0 Likes
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Car: 87 IROC
Engine: 420 EFI
Transmission: TKO500
Axle/Gears: Moser 9" 3:50
Re: Possible Bad IAC?
Hi Guys,
The Autozone lifetime IAC was bad.
An AC Delco was installed.
A photo of the old IAC is attached. It shows the internals of the valve.
Best Regards,
Briuce
The Autozone lifetime IAC was bad.
An AC Delco was installed.
A photo of the old IAC is attached. It shows the internals of the valve.
Best Regards,
Briuce
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