My 83 Chevy 350 started having a stalling problem intermittantly, or would just crank when you tried to start it. Strange thing is that it would crank and do nothing but will shudder like it wants to start when the key is returned to the off position. Replaced module, coil, cap, rotor, plugs, fuel pump and still nothing. Any ideas, this is driving me nuts. SBC with HEI distributor.

 

If it tries to start when turning the key to the off position have you considered a faulty ignition. Maybe something isn't getting power when the key is in the start position.

 

well first things first......will it fire on carb cleaner?.........if so you have a fuel issue.....also check the fuel pressure.....even though you changed the pump the problem could be else where....also like shamrock said check all power that should work with key in start and run positions