1987 Chevrolet Monte Carlo 87 SS idle problems

DFORE2

MEMBER
1987 CHEVROLET MONTE CARLO
5.0L
V8
RWD
AUTOMATIC
187,000 MILES

Carb. Not idling correctly. When the engine is cold it idles fine. When it warms up it wants to idle below 900 RPM and sometimes drops so low it stalls. I can turn on the AC and after a few minutes it idles up. Yesterday I was driving without the AC and before I even came to a stop it stalled. Could this be a vacuum leak somewhere. I have a quadrajet that I bought new several years ago and never had this extreme of a problem.

1 Reply

HMAC300

MECHANIC
48,601 POSTS

Quadrajets, get vacuum leaks internally it may be just stuff inside carb or depending on how old the carb needs a rebuild due to alcohol. If you go to power nation tv and look up your carb they show how to fix the internal leak. Also if it has a plastic float in it the alcohol may have eaten it up in the center so it doesn't maintain correct fuel level. But her eis something to try. Take air cleaner off, rev motor and close choke with your finger til it wants to stall then open choke so it will keep running. Do this a couple of times and then if you can remove your air adjuster screws take them out and spray choke cleaner in the holes then reinstall them and put at 1 and 1/2 turns out from being lightly seated. Then start car and try to adjust air screws to highest idle or vacuum if you have a gauge. What it does is clean needle and seat of crap in it if there is any. It may idle better as well.