Welcome to the world of automatic chokes:
Poorboy has pretty much covered the bases but I will add my

Make sure you have 12V to the choke. Many will try pulling power it off the coil which may only be seeing 8 or so volts.


What Many don't understand is there are several things interacting to get the choke functioning properly.
1. Preload on the butteryfly when cold,
2. Choke pull off adjustment
3. Butterfly position once started
4. Fast idle cam position
5. Fast idle adjustment
6. How long the choke stays on

If there are no markings on the housing use a sharpie or scribe to add one to the main choke body (botled to the carb) and a few evenly spaced both directions on the housing that rotates

A critical part of the process is in RED. if a motor has not run for more than a minute an 8 hour cold down may suffice. More than that, I'll make the adjustment I think it needs and leave them overnight.

Other items that come into play are a bumpy cam, loose mechanical advance that may make it hard to get a stable "fast idle" setting

The higher the fast idle is set the more the butterfly needs to be opened by the pull off. This is due to the engine needing more air or it will run rich.

if it is open too far the engine will stumble due to being to lean.

With the throttle open a 1/4 way or so The butterfly should close all the way with a light forefinger tension required to open it. When the finger is removed the Butterfly should close all the way with a light tension I want to say snap shut but lightly so.

With the butterfly closed, close the throttle. It should stop about .100 or a bit more from the hot idle screw

Open the butterfly so a 1/4' drill bit fits between it and the carb throat. (simulates the choke pull off opening the choke on a cold motor)

Open the throttle slightly to release the tension on the fast idle cam and release the throttle.

The throttle should now stop about .060 or more from the hot idle screw (if the fast idle is adjusted correctly.)

Are we having fun yet?

One thing to keep in mind: the choke preload only determines how long the choke takes too fully open. it is the other adjustments that determine the engines behavior when cold.

it can be frustrating if you do not understand how all of the above interact. Loose mechanical advance or a lumpy cam will aggravate the process but can be worked around with adjustments and tweaking

This is a trial and error process that may require several attempts to get it right. Every motor is a bit different unless stone stock. Even then they may require a bit of tweaking from the factory spec'd adjustments Once done they are wonderful. I love to fire my car up at a show have it run on a slight fast idle, blip the throttle and have it drop down a bit, put it in gear and drive out with no stumbling popping spitting etc.
hope this helps and keep us posted

Poorboy and TJP have it down pat. I spent a lot of years building/rebuilding/tweaking carbs. Living in WI we got real good at tweaking stat housing and choke pull-offs. One of the biggest reasons there is no choke on my toy...hop in, pump it a couple times and start it up. Feather the throttle for a few and good to go. I've fired mine up in Feb when the temps were WELL below freezing...took a bit more to keep it running but it fired right up! 470" with a Holley 800 DP.

Two shots from that double pumper helps with richening that mixture up LOL,
I see it as a challenge and love them When set up. My 38 ( 340 6 pak with mechanicals) can sit for a year. Key on, elect pump on, 2 or 3 pumps it'll start and die. two more pumps it starts and idles at about 1300, after30 seconds or so , blip the throttle, now at 1100 or so, drop it into gear and drive way
Had a 64 Dart years ago with a pretty radical 340 in it, no choke. Loved it when cold as it had a different even more radical sound to it especially when blipping the throttle to keep it running
I've always hated the cheesy aftermarket manual choke kits that cause more trouble than setting the automatic choke up IF one knows how they work. Most do not take the time to do so and blame the choke.
But this is true of most everything. When I taught classes on equipment I always told the students the first 2/3 of the class was the most important as we would break the machine down into subsections, Learn how each section functioned, then start reassembling to UNDERSTAND how they interacted with each other.
If one knows the above, the machine will just about diagnose itself by its symptoms.
Or one throws parts at it sometimes getting lucky and others creating more problems. In the second case they normally call it a POS and blame the item. Quadrajets, Carters, Edelbrocks, Holleys, Strombergs, and most others are all good carbs. They all do the same thing, but differently. One needs to know how they work before they can repair them. NOTE: I left Demon and Predator out purposely. the early Demons had some issues IMO, not sure about now.

I live in northern IL and I drive my stuff year around. Since I know how to properly set up automatic chokes, every carbed car I've ever owned, and drove on the streets, had a properly adjusted automatic choke. When they are properly set up, the motors run correctly from stone cold (-30 F) to dully hot (+90F). I can not understand how people can stand a poorly running car at any temp. Maintaining proper automatic chokes is just like maintaining anything else on a car. There are things you have do to keep functioning, but once set up, maintaining an automatic choke isn't any more difficult then maintaining any other part of a car.

Even my street drive high performance cars had operating automatic chokes. Our dirt track cars did not have a choke, but once those started up, it was past the need of a choke.