1947 Chrysler auto choke

[caddy60s]

I seem to be having difficulties using the auto choke. Up until a month ago I would depress the gas pedal about 2/3  of the way down and a few cranks the car would start.  Unless I get under the hood and flip the choke up it dose not respond to the gas pedal routine.  I found the lever on the auto choke very stiff to pull up. I cant see any restrictions causing this so I though I would 

seek advise.

Bruce Watson

[TerryB]

Can you take a picture of the setup and post it here?

[ojh]

Carter BB, 'Climate Control' choke  They're pretty basic.  See if the linkage rod from the throttleplate to the choke housing is hung up of if the choke flap (they call it the choke valve) may have lost a screw and is hanging up (not likely).  Inside the choke cover you'll find a spring that closes the choke valve and tucked away where you can't see it is a vacuum operated piston, both spring and piston deal with the automatic operation of the choke.

Edited October 14, 2020 by ojh
speeling (see edit history)

[auburnseeker]

Is it this type of choke like the one mounted on this manifold? 

[61polara]

1 hour ago, auburnseeker said:

Is it this type of choke like the one mounted on this manifold? 

This is the type choke you should have with a rod from the arm to the choke arm on the carb.  This was a very advanced system for the day as it is an electric choke.  Pressing the accelerator pedal does not engage the choke.  There is a wire coming out of the top of the choke connected to the starter relay which engages the choke when you press the start button.  The bi-metallic spring inside slowly releases the choke as the engine warms up.

[caddy60s]

Thank you all for your interest  and information ,

 

Bruce

[auburnseeker]

Those chokes do work very well and were used for atleast 20 years.  They do fail eventually but NOS replacements are easy to come by and not too expensive if you look. Usually under $100

[c49er]

The 1947 Chrysler choke on the manifold is called a "Sisson" choke.

Shown above is the 6 cylinder choke unit.

The 323 eight cylinder Sisson choke units look similar but have a rectangular black box cover on top and are very hard to find new and costly.

The choke unit mounts over an asbestos heat controlling gasket on the exhaust manifold. Prevents the choke plate from opening too soon.

Adjusted correctly these choke units are and very reliable.

[Paul S]

Actually , depressing the accelerator does set the choke, when actuating the starter , voltage is applied to the choke solenoid, closing the choke all the way while on the starter, than it operates like a normal automatic choke with the bimetal spring.  There is a setup procedure using a pin thru the hole in the shaft.