gow/Godspeed

I have recently done a headgasket replacement on my 93 3slow pickup
My latest problem is that it wont start anymore
after replacing the injectors I took it out for a spin to try them out
it ran great except underload or when i punch it it would accelerate fine
then suddenly seem like it completly shut off but if i let of the gas for a
couple seconds i could accelerate again but not for long before it would do it again
the next time i tried it it did this same thing but did not start again
I had to have it towed
now when I try to start it it turns over starts for a second then dies
have any ideas?
I was thinking maybe the fuel pump