1980 Chevrolet Monte Carlo Weird revs and stalling

1980 CHEVROLET MONTE CARLO

164,000 MILES

CRASHBORD

MEMBER
1 POST
FOLLOW

I have a 350 small block, think its been rebuilt, quadrajet carb, original tranny to the 80 monte Carlo, and a header leak. Don't know if that's relevant but what the hell. Last time I drove it the exhaust had a bit more smoke than usual and smelled weird. Next time I started it the idle wasn't right, kinda wanted to drop out and stall every now and then but never did. When I tried to drive it I revved it and it really didn't sound right then when I let off and coasted a bit it stalled. Started again no problem but letting off the gas while moving resulted in stalling again. Thought maybe fuel filter or idle screw adjustment? Looking for some knowledgable advice before spending money and messing with it though.
Thanks

Jun 12, 2013 at 4:33 PM

HMAC300

CAR REPAIR CONTRIBUTOR
48,601 POSTS

this can be anything, partially due to the alcohol in todays fuel. it may have taken your accelerator pump out. or being a Rochester they are famous for internal vacuumleaks. Powerblock magazine one of the issues has a very good article on rebuilding the carb and stopping the vacuum leak you might want to check that out. It could also be valve seals as well for the smoke and header leak could be bent at flange and you need a different gasket. if you try an adjustment , remove screws spray choke cleaner in there then pt screws back in and seat lightly not like a gorilla, back them out 1 an dhalf turns then turn either way for highest idle. then readjust your idle

Jun 13, 2013 at 10:43 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.