Trouble with idling

[gacs]

I have a Rochester carb in my 1977 Cutlass and when I put the car in Drive, it idles very rough, at times even stalls. The engine runs smooth when accelerating and in cruise. What are the possible causes? Thanks

[1BADOLZ]

Could be as simple as a vacuum leak. Spray the intake and carb base with carb cleaner and see if you get any surging. Or just feel and inspect vacuum hoses wiggling and feeling looking for cuts or holes, loose ends or anything disconnected.

Lots of possible trouble areas but start with simple things first.

[gacs]

This carb was freshly rebuilt. Thanks but I will do as you suggest.

[1BADOLZ]

Spark plugs? Loose plug wire? Fuel mixture screws adjusted correctly? Vacuum leak? Adjust the idle up a little?

Could be lots of things

[damaged442]

Check the timing.
Make sure all 8 cylinders are firing.
Check all spark plugs/ wires. How do plugs look?
Check condition of make sure distributor cap/ rotor are on tight.
Play with idle screw on side of carb.
Check rich/lean.
You may even have bad gas or clogged fuel filter. Gas with ethanol does attract moisture.