'79 302. I rebuilt my factory carb but it still has a real hard time staying started from the get-go, regardless of the weather temperature. I've gotta turn it over, lay on the gas to keep it from stalling and once it'll run without the accelerator pushed I still have to let it sit for a minute because it'll stall once a load is put on it. I've adjusted the carb as good as my knowledge allowed, but in park it currently revs fairly high.

 

I am almost positive that it is a throttle position sensor, or electronic choke. Warm it up and see if the choke is open. If it is then check the TPS.