Okay so all week I have been struggling with my mav. I have a stock carb that I have rebuilt, stock v8 engine, and I'm running straight pipes ( not sure if that matters). When I start the car it idles high yet when driving fast or coming off the highway and stopping at a stop light the car idles low to the point it kills itself I'm not quite sure whats up. Any ideas or suggestions?
First of all if the car is cold when you start it up, the fast idle could and should be due to the choke functioning properly, so from there, warm the car up to proper operating temp while sitting still and when the idle drops off (choke opens) see what it idles at then, if its a real low idle you can try and adjust it up a bit, if it is a rough idle you may have a vaccum leak, there should be an idle adjustment on it.
I have no clue what choke is on the car, I haven't replaced it so I assume the one that came with it.
If your car is running fast with the chock closed, this is normal with a cold engine. When the car gets warm, and the chock opens causing the engine to lower the rpms at idle. Do as the others said, crank the car and let idle until the choke opens, and then set the idle to approximately 650 rpms. If you do not have a tachometer you can turn the screw on the idle adjustment clockwise to increase the rpm up to a comfortable sound. Try doing this until you can stop the car on the level without chocking down, or creeping forward without your foot on the brakes.
all the coments on the choke are correct. the open exhaust can also contribute to the the stalling. a motor needs some back pressure to run correctly. you should be able to raise your idle rpm and that should take care or your problem
Do you have a dual vacuum distributor? Past thread here - http://mmb.maverick.to/showthread.php?t=72133
No engine "needs backpressure". For maximum performance, the intake system needs to be matched to the exhaust system, but an open exhaust would not cause stalling.
