1973olds98

Does anyone have a diagram of the choke assembly on a 1973 rochchest 4 bbl carb..My choke is not working when i bought the car...I didnt know it until i got it home..The arm of the choke has a wire threw it tied down so it will not operate..I unhooked the wire and gave the car some gas and the arm kicked up and the plate closed on the front part of the carb..The problem is it never kicks off....

Olds64

IF the choke never disengages then you need to reset it. Loosen the three screws on the choke plate and use a screw driver to turn the choke in its housing until you get the choke plate to move. Do this with the engine cold. When the choke plate moves make sure it is closed with only a little bit of space between the choke plate and the body of the carburetor. Then retighten the three screws.

1973olds98

So i turn the black cap in clockwise?

1973olds98

OK,,,its counter clockwise right? I move it in counter clockwise with the motor cold just until the choke plate closes on the carb

Olds64

Moving it clockwise or counterclockwise a bit should cause the choke plate to move a bit. Just move it whichever direction causes the choke plate to close.

1973olds98

OLDS64

thanks man,,,I got it reset and it work now...Should the choke plate be straight up and down when the engine has warmed up...Mine is opening as it gets warmer but dosent go straight up and down...

Olds64

The choke plate will eventually open up completely but you have to "blip" the throttle to deactivate the fast idle cam. It may take a minute or two.

1973olds98

Yep,,its working,,,,,So basically if you turn the black cap more it will take longer for the thermostat spring to open correct? How high should it idle when the choke is on...? And what should the idle be when the choke is off

Olds64

No. Changing the position of the black choke cap causes the choke valve to move. This allows you to close the choke when the engine is cold. Remember that your choke valve will end up more open or closed once the weather changes. The position of the choke plate is dependent upon the bi-metallic spring inside the choke. This bi-metallic spring is swedged onto the black choke cap and wraps around the bottom of the choke rod.

You set your fast idle to determine the idle speed in park with the throttle plates on the lowest step of the fast idle cam. Set the slow idle with the choke disengaged to determine your idle speed in drive.