Need some help guys, 66 coupe/289/summit carb 4barrel 600 cfm/auto trans/car turns on great idles great and all but when at red light and been there a couple of seconds the car starts wanting to quit on me. Thing is as soon as I give it has it responds very well or if I put it back to neutral or park it idles back to normal as if nothing was wrong. Another thing is when I have it in gear and it starts to quit on me if I place my foot on the break and gas it works perfect no problems when i take off. It is just when at red light or stop sign for a couple of seconds. Spark plugs wiring set has been changed. Also have changed from points installed the pertronix with its coil. Thanks in advance peoples....

 

Usually cars with carbs need to be idled up a little in Park/Neutral so they don't stall in drive or reverse.

 

if you have power breaks pinch of the vacuum hose to the booster and see if the engine speeds up a little .. could be a leaking booster .. and as SpectreH suggested bump the idle up perhaps 100 rpm .. there are many things that can be wrong ...do you have an aftermarket cam ? ..

 

I have been told by a mechanic that it does have an aftermarket cam. How can I find out if it does? I don't really know a lot about mechanics. I know the basics oil change wiring spark plugs. Once I get into the motor I don't really know a lot. Thanks again.

 

listen to the exhaust .. if it has a bit of rumpty rumpty idle it must not be stock .. if it is smooth it will be stock .. a non stock cam changes all parameters and tuning but is not necessarily a concern .. just bump up the idle a bit and see what gives ..make sure it does not continue running after you turn the switch off ..

 

Your ideal should be at least 750 RPM while in drive at a stop.
Where is your idol now while in drive and stopped!

 

no it goes down to 400-500. The thing is it works fine and all but I just noticed after it warms up and am at a stop or red light it starts doing that. It does sound like it has a cam it actually does that. Like I said the car works well like a champ on the highway it's just when I stop for a while on gear.

 

Raise your idle by about 200 rpm, that should fix your problem.
idle does not affect the way the car runs any other time other than idle!
400-500 is low for a stock motor if you have a performance cam that's way too low!
Like I said set it to about 750 rpm while in drive and stopped!

 

My /66 auto acted goofy like that once in a while 'till I put a "anti-stall dashpot" on it. Runs, idles great now., Mark

 

even if it has an aftermarket carb sir?

 

Yes. It's to slowly return the throttle plates so the engine isn't starved for fuel and stall out.

Adjust your idle to 750 in drive, like has been said, install the dashpot on the throttle linkage of the carb, and that should help you out immensely.