I have a 82 Z28 with a 350 V8 (not the original, its a 78 block). The carb is a Holley Street Avenger 670 w/electric choke. I tried ajusting the idle screw, but it has no effect. I can turn it in almost all the way and it does nothing, and turn it out till it almost falls off and it has no effect. Should I be looking at the fast Idle screw? Im reading on Holleys website, but I need some more help.

Also, it seemed like the choke wouldnt turn off, because the choke light on the dash was on nonstop. But I unpluged the positive and negative wires going to the choke, and the light stayed on, so its probably just broken.

 

Might be to rich also. Check your idle mixture screws.

 

my holley did that i got a stronger return spring to pull it back and touch the idle screw then i adjusted the screw. just go to napa and get the biggest one and bend the ends to fit. hope this helps it worked for me