Hello i've been having this issue with my chevy. I would start it and walk back inside my house to let it warm up or so i thought. Everytime i would come back it would be turned off. So i started sitting inside the truck while I warmed it up pressing the gas pedal every 20-30 seconds for 2 or 3 minutes. If not it would imidiatly stall when i put it in drive and press the pedal down. Sometimes when i'm pulling out of my drive way and put it in drive I hear it about to stall i would let off the gas real quick and that seems to keep it from stalling like i could hear it ignite gas again and i would press down on the gas and its fine. There's a busy intersection about a mile from my house that I need to cross everymorning and if i have to be waiting to cross it for more than 20 seconds i have to put it in park so i can rev the engine to keep it from stalling. Any thoughts or suggestions?

Make
-1980 Chevy Custom Deluxe 30K
-Drivetrain Layout 4WD
-4 year old rebuilt 350 Engine
- 4 door 3/4 ton
-Carburated Engine ,oil and tranny fluid changed less than 200 miles ago.

 

Sounds like you may have a vacuum leak or maybe a defective accelerator pump. It may be time for a carburetor rebuild kit. Or possibly it just needs a good cleaning. I'd try a can of carburetor cleaner first. It's the least expensive place to start.