1960s '66 Carter carb choke system

[Julien Abrahams]

1966 Eldorado Carter carb.

I am working on the Carter carb of a '66 Eldorado. It has the hot air choke
I have question with regard to the choke system. I understand that the thermostatic coil keeps tension on the choke lever, so when cold that makes the choke close.
I have the choke cover off and the thermostatic coil removed fron the housing.
However, the choke does not fall open so to say. Am I missing a spring somewhere? Or is the choke "pushed" open by the difference in air pressure between outside air and manifold vacuum?
It has been a few years since I last opened a carb, and this was Rochester from '67 which has a divorced choke.

Also, the housing was ful of soot and carbon deposits. So.I guess the choke tube inside the manifold has rusted through. For now I do not want to removr the intake manifold (as they are prone to cracking and virtually impossible to find).
I was thinking to either install an electric thermostatoc coil. Or to fabricate some tubing to wrap around the intake crossover or the exhaust manifold and see if that heats the coil enough.
Any tips are more than welcome.

[TJ Hopland]

If it was full of exhaust the spring bits likely got cooked so they are not springing right so that may be why its not making sense.    In the USA you can still walk into any parts store and pick up a choke kit for a Edelbrock carb off the shelf.  I do recall there were slight mods required to the kit parts to make it fit at least on the 1957 carb I last did it on but it wasn't too bad.

There are several kits out there, you are looking for one that comes with the cast housing but not the long shaft.  I don't remember exactly what I had to modify it was something on that new cast housing that had to be ground to clear or fit over the original carb body.   

[The Tassie Devil(le)]

1966 Eldorado Carter carb.

I am working on the Carter carb of a '66 Eldorado. It has the hot air choke
I have question with regard to the choke system. I understand that the thermostatic coil keeps tension on the choke lever, so when cold that makes the choke close.
I have the choke cover off and the thermostatic coil removed fron the housing.
However, the choke does not fall open so to say. Am I missing a spring somewhere? Or is the choke "pushed" open by the difference in air pressure between outside air and manifold vacuum?
It has been a few years since I last opened a carb, and this was Rochester from '67 which has a divorced choke.

Also, the housing was ful of soot and carbon deposits. So.I guess the choke tube inside the manifold has rusted through. For now I do not want to removr the intake manifold (as they are prone to cracking and virtually impossible to find).
I was thinking to either install an electric thermostatoc coil. Or to fabricate some tubing to wrap around the intake crossover or the exhaust manifold and see if that heats the coil enough.
Any tips are more than welcome.

The choke thermostatic spring does two jobs.   When the engine is cold, it holds the choke closed, and when hot, holds the choke open.

Remember that these springs are a bi-metallic style.   That is two pieces of material fused together.   One side contracts when cooled, and expands when heated.   The adjacent side is there to hold the moveable bit in shape.

As the engine warms up, the exhaust heat heats up the spring, to open the choke.   But, let the engine cool down, say, when parking whilst out shopping, the spring has less heat getting to it, so it cools down, always ready to operate the choke when the driver decides to start the engine up again.

Pretty simple, but a real pain when one doesn't want the choke operating during the day when using the car, as when the choke comes on, the fast idle also comes into play.

Bruce.