al714

in the morning when i started my car i gave it some gas and noticed that the rpm on it increased and just stayed that way.. when i checked the carb i noticed that the throttle lever dosent come in contact with the adjusting screw..my question is ..is it the spring that makes it come in contact with the screw or something else.( kind of new at this).any suggestions thank you...1972 cutlass supreme 350 4bb carb

MDchanic

The little plastic counterbalanced fast idle cam is stuck.

Spray a whole lot of Gumout on it and move it back and forth and it will be fine.

- Eric

Lady72nRob71

The above will surely help.

My old Ford had this problem for a long time - I had to pound the pedal to get the fast idle to drop.

The cause was mostly from me - I oiled and greased the linkage.
This caught lots dirt and grime and the grease eventually hardened and turned into a paste. The cam drops by gravity and needs to be free moving.

My fix was to remove the choke assy, disassemble it completely, soak the parts in degreaser, scrub them clean (including the hole in the cam), bake dry, reassemble and do not use any lube on them.
Now, just a small nudge on the pedal will drop the fast idle cam, to both positions, too.

joe_padavano

WHICH adjusting screw doesn't make contact? Keep in mind that if the choke is on, the fast idle cam will hold the slow idle screw off the stop until the choke is fully open. That is normal. If the choke is not opening properly when the engine is fully warmed or if the fast idle cam is not being moved to the slow idle position, that is a different problem and needs to be fixed properly.

al714

here are some pictures.. sorry if they look bad..also this is my daily driver is it safe to drive? what should the rpms read. as of now when on parked it reads 1000 rpms..

Rickman48

Look on the other side of the carb - kinda under the choke, and you'll see a 'fast idle cam' that comes on when the choke closes!
Squirt some carb cleaner back there, and make sure everything is freed-up!
Move it with your fingers, and spray it again!

MDchanic

Yup.

Those are pictures of your slow idle speed screw.

You'll find the fast idle screw and cam on the other side.
The cam is plastic and is probably some color (blue, red, white, yellowish).

- Eric

Lady72nRob71

Look on the other side of the carb.
My 72 350 4bbl looks to have a metal fast idle cam, circled in red in the picture below. Fast idle screw is down in there somewhere...



It it does not move freely (throttle held open some), then that may be your issue.
Driving with it stuck could be dangerous and not good for your tranny in stop and go traffic.

Oldsguy

Do this after the engine is warm and then turn it off, no need to race the engine to OMG rpms.

al714

it was the metal cam that was stuck ..started to move it and as soon as it got loose everything was back to normal...thank you everybody for all the help