Mostly the car has been idle since I finished rebuilding it recently. On the freeway a couple of times, but mostly sitting there.
So I take it to the grocery store, which is about 3/4 mi. away. I choke it and it starts right up. Good. I take it onto the street - driving on kind of 1/2 choke - and engine starts to rapidly go up and down between racing and dying out. Using my long learned choke and clutch manipulation skills I make to the grocery store and sit at an "idle". It smoothes out a little as I sit but when I turn it off it kinda runs on even though the ignition is off. After buying my two cents worth in the store it starts right up and runs smooth as silk for the ¾ back home. When back in the driveway I turn it off and the engine goes back into its staying on routine.
This is a newly rebuilt '69 B20, bored out with an Isky cam in there. It has a vacuum advance upgrade (unit from a mid-seventies Saab).
Before I go back and totally recheck the timing and totally readjust the carbs again and again and again, can anyone recommend what might be going on with this engine?
Shouldn't I be able to drive this car before it's warmed up? Must I sit there while the pretty much new engine warms up completely? And what causes the engine to run on after the ignition is off?
Man, this is frustrating!