General Category > Quadrajet Carb Talk and Tips

67 GTO 7027262 Fast Idle

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rickmpontiac:
I removed the carburetor today and confirmed the HIC has been plugged. See attached picture.

I also checked to make sure all the throttle blades were centered in the base plate.

The car idled fine, meaning it could be adjusted down to 500-600 RPM with an Edelbrock Performer manifold and Edelbrock 750 CFM carburetor. I installed a correct casting cast iron manifold when I installed this carburetor. All this to restore the originality of the car.

Is it possible that I have significantly more vacuum to the distributor advance now (24 degrees advance at idle) with this configuration?

Just trying to determine what would contribute to the high idle speed.

Kenth:
Timing is fine, factory setting is 6 degrees BTDC initial plus 20 degrees from the vacuum advance.

Air is getting past the throttle somewhere. Common leak paths include the carburetor and throttle body gaskets, carburetor insulator spacers, intake manifold gaskets, and of course, any of the engine vacuum fittings, hoses and accessories. Another overlooked item can be a worn throttle shaft.
At this point i would look at the throttle body gasket for correct style and the intake surface may have been milled in the past to fit milled cylinder heads causing an intake manifold gasket leak?

rickmpontiac:
Thanks everyone for the advice and lists of things to check out. I am still doing some investigation and will be back with more information soon.

Mr.Pontiac:
Rick the hole in HIC is not ware screw is , it’s on top of the HIC passage towards top of bady

firebird400:
Thx for this post here guys & Gals , I have similar issue and will be using this info to deal with my situation.

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