Adjusting electric choke on Holley Street Avenger
I have a model 80670 Holley street avenger carburetor on my 67 Chevelle. When I start it, and the engine is cold, the electric choke closes as it should, but only for about 15-20 seconds then it automatically opens up to about 20%. When the choke opens and the engine isn't warm enough, the engine dies. After re-starting, to keep the engine running I have to feather the gas pedal until the engine temp reaches about 150 degrees or it will die again.
My question is: How do I adjust the electric choke so the choke remains closed till the engine is warm enough to support both AIR and GAS?
You can increase the tension on the choke loosening the three screws and turning the cap counter clockwise. I would turn it one index mark at a time. You will want to set the fast idle speed around 1500-1600 rpm. The easiest way to set the fast would be to have someone start the engine cold and turn up the curb idle speed to your desired fast idle speed. At that point, you will know what throttle angle you need for fast idle. Next, manually close the choke and adjust the fast idle screw until it touches the fast idle cam. Restart the engine and warm it up. Kick off the choke and reset your curb idle speed. If the choke still opens too fast. You may want to look into an electro-dyne heat sensor. Holley number 45-267.
Thomas R. Kise
Holley Tech Service