74 carb high idle
Thread Starter
Racer
Joined: Sep 2012
Posts: 420
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74 carb high idle
My vette on a cold start up idles at about 3 gran a little more then I would like. Would I be able to just adjust the high idle screw ?? Would this affect anything else in a negative way ?? I would like to set it for around 2 gran ??
Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
The engine compartment should have a label that shows the fast idle spec.
Absent that, first get the engine fully warm. Turn the engine off and open the throttle just enough to pull the fast idle cam (on the right side of the Quadrajet) under the stop with your fingers. Now start the car without touching the throttle. Using the screw adjustment, set the fast idle to 1500 RPM with an automatic, or 1300 with a clutch. This will give you about a normal idle speed when the engine is cold. Adjust in 100 RPM intervals if you are unhappy with your first result.
Absent that, first get the engine fully warm. Turn the engine off and open the throttle just enough to pull the fast idle cam (on the right side of the Quadrajet) under the stop with your fingers. Now start the car without touching the throttle. Using the screw adjustment, set the fast idle to 1500 RPM with an automatic, or 1300 with a clutch. This will give you about a normal idle speed when the engine is cold. Adjust in 100 RPM intervals if you are unhappy with your first result.
