So you have a Holley with an electric choke on your car, and it gives you fits a cold startup.. Adjusting the choke by spinning the black cap really doesn't do anything. My Cougar had this problem. When cold, I'd start it, engine would go to fast idle around 1500 or so.. stumble then die.

Start again, same thing.

If I started it and kept my foot in it to 2K, it'd run.. very rough, for about 45 seconds. For a street engine this really shouldn't be the case at all. Some digging around the net led me to this.

I found the adjustment procedure for the "Choke Pull Off". Basically this sets the absolute smallest the choke can go. Some playing with my Cougar got me to the point where I realized that even totally cold, the choke needs to be opened some. Spinning the choke cap just adjusts the 'rate of speed' that the choke opens. It was always closed too much at cold start/fast idle, regardless of the adjustment.

Anyway.. What you're looking for is illustration #15 on this.

http://holley.com/data/Products/Technical/199R8339.pdf

Holley neglects to mention this setting in the manual that comes with a new carb... and they don't mention it in the manual for an electric choke! Lots of people seem to have this problem (I've seen other Holleys with this start up issue as well). This is the fix. You'll have to ignore the paper clip setting, and play it by ear a few times.. but this rod is meant to be bent. Try a few different settings.

Edelbrock carbs and Qjet carbs have a similar adjustment.

I know there's a few carb heads here, this should give one more adjustment to get your car running like an EFI car.