Throttle stuck wide open

[Datsun pickup]

I have an ‘85 720 2wd and the throttle is stuck wide open when I start the truck. I don’t know if there is a check ball.

Edited February 26, 2022 by Datsun pickup

[datzenmike]

Do you mean a fast idle? on cold start up, but is ok the rest of the time once warmed up??? That would be normal on a carburetor with it's choke on. Fast idle is 1,800-2,200 RPMs. It simply makes driving a cold engine easier and speeds the warm up.

 

 

If you mean it revs to the moon and is undrivable, take the top off the air filter housing and look down inside the carburetor with a flash light. One of the throttle plates must be jammed open or part open.

[Datsun pickup]

I didn’t run it very long at all and I didn’t check the plates, because it sounded like it was going to run away. There is also a fuel leak coming from the fuel pump assembly on the carburetor.