1981 High Idle?
Thread Starter
Instructor
Joined: Jan 2022
Posts: 144
Likes: 15
From: Texas
1981 High Idle?
Interesting new problem; out of nowhere my '81 started doing a high idle at 2,000 RPM only when in the park position; and the engine wants to keep doing a run-on after I turn the engine off. It used to idle around 1000 in park and about 2 weeks ago it just shot up for no apparent reason that I can find. Idling at lights and in drive/reverse is completely normal at about 900 RPM. I've also noticed that when this has happened (not sure if its a coincidence or not) I've noticed my gas mileage decrease significantly; decreased almost by 20 MPG per tank. I do have a 1980 Rochester Quadrajet carburetor on this vehicle if that helps at all; at first I thought it was the idle speed solenoid acting up but I'd like to get a few opinions before I go replacing stuff.
Race Director
Joined: May 2006
Posts: 18,695
Likes: 2,572
Is the throttle lever touching the solenoid with the engine running or do you see a gap? If there is a gap something is preventing the throttle from closing. Puzzling how you can use an 80 Quadrajet on an 81. 81 had an electronic Quadrajet, primary power valve controlled by computer as well as distributor.
Race Director
Joined: May 2006
Posts: 18,695
Likes: 2,572
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
Is the connector to the heated choke connected, and is the choke heater working? Take the air cleaner off, start the car, let it warm up. The choke should fully open. It sounds like it's not opening fully, which results in a richer mixture, and poor gas mileage. Also, there should be a carb heater hose hooked up from the exhaust manifold shield to the air cleaner. That will also help the choke open up. This is assuming everything is stock.
