I am working on a 66 442 right now and the choke spring seams to be very slow to curl up and pull the choke open. There is no binding and it looks to be hooked up right.

 

Yes, metal fatigues with age and use - it's a cheap and easy replacement.
You could even switch to an electric choke, with a little more money and effort, but much nicer results!

 

It's not a cheap replacement and also hard to find

 

If the spring is intact, you might check and see if the tube from the manifold is clogged, or if it's the type that bolts on the intake manifold, the heat passage in the manifold itself might be clogged!

 

You all need to go back and read the original post. This is a 1966 442 with the divorced choke. There are no tubes to clog up and as noted, replacements are NOT cheap.

 

Which is why I included possibe clogging of the crossover passage - which heats the spring!
Don't know if the spring can open slow unless it's not getting hot fast enough!
Even partially clogged could slow it down!
I know I've spent up to an hour 'unclogging' manifolds, as even hot tanking won't get the baked carbon, soot and oil out!!

 

OK, sorry. I read your response as clogs in the tubes for the hot air integral choke. On the other hand, I've never seen an intake crossover that was clogged, either.

 

Yes, choke coil springs do wear out. I don't know if it's the metals changing characteristics (losing their "spring") or corrosion gumming things up. But my experience is they lose their range of motion. That is, for the same change in temperature, an old spring will move less than a new one.

 

I checked it with a heat gun and it does seem to open pretty quick. Idling in the driveway it does not seem to open but just driving around a few blocks it was wide open.

 

Is the 'heat riser' still on the car, and functioning correctly?
That'd help a ton, and the reason it's there.

 

The hot air intake as stated previously is very important for smooth winter operation. Long after fuel injection ruled the roads I was driving my 72 Eldo with Q jet in temperatures down to zero with no problems starting or warming up. It had the coil spring mounted over the crossover and a functioning heat riser.