Fast Idle on 81'

[rebart]

On cold start my 1981 idles fine at about 1000 rpm's, but once she warms up, she idles at about 2200 rpm when in Park or Neutral. All the vacum lines are connected....How and where do I turn the idle down ??

 

[C3 4ME]

Teh fast idle is a screw on teh passnger side of the carb, idle is on teh drivers' side. Look at where the linkage connects and it should make sense for the regular idle. Both idle screws on a Q-jet point toward the front of the car. Dont' confuse them with the mixture screws on the front of the carb, both of these screws are on teh sides of the carb.

 

[rebart]

Thanks C3 4ME ... Do you know, which way I need to turn the screw to reduce Idle speed ??

 

[Peer81]

When you look at the sticker that is on the inside of your 81 hood (if it's still there) You'll see that the fast idle speed (cold) should be at 2200!
When your engine drops out of the choke it should drop to 500 till 600 rpm. As far as i know the cold fast idle will be reached not in one time but in steps so it begins at around 1000 and then it will clime to 2200.
Turning back the screw will have no effect because your engine is still running on the choke. When it drops out of the choke it will return to the 500 or 600 correct? You force the engine to do this by just pressing the gas pedal a little. Your choke is also ECM controlled so there is another thing you'll need to do. You can control the fast idle speed and the moment it disengages with the choke. I would find out how to do this and your problem will be solved.

This is when your original ECM wiring is still in place and the ECM to but is sure sounds like it!

Greetings Peter.

 

[rebart]

When the choke is on, my engine rpms are aroung 1000, but when the choke disengages (my choke light goes off), thats when th idle speed climbs to 2200 and stays there...??? So what does this mean ??

 

[C3 4ME]

turn either one counter clockwise to reduce idle speed.

 

[Peer81]

Then go with C3 4ME's option
Sounds like you have a early 81, later BG one's don't have the Choke light anymore.

Groeten Peter.