injectors wont spray 1990 blazer k5 350 5.7 4x4

Hi I got a 1990 blazer k5 4x4 5.7 350 full size blazer that im having promblems with the injectors wont inject they wont spray first we thought it was the fuel pump and fuel filter but it wasnt it or the computer it aint none of that. the stragest thing is if I get a piece of wire and wire it to the injectors to place it to ground the injectors will start working they will spray alot but it get flooded so we bought a new computer it still the injectors wont work they wont spray. Im out of ideas please help