Chevrolet Repair: 1996 sierra pu, body c, v6 engine

Question
I have a 1996 sierra pickup with a v6 engine.  The engine would not start.  If gas was poured into the throttle body, the engine would fire and run until the gas was used up.  Based on this finding, I replaced the fuel filter and the fuel pump.  The engine will now start and run at idle, however when the accelerator is pressed the engine will stall.  I am not sure where to go from here.  Any suggestions would be appreciated.

Answer
Hi Roy,

When pouring the gas in, could you press the accelerator and get the same result?  

I wonder if there is a bad injector.  Or a bad vacuum issue.  Maybe a fuel pump pressure regulator.  Do you have a pinched line?  What is the pressure at the rail/thrttle body?

C J S