1988 chevy stepside 4x4 fuel pump problems

i have a 1988 chevy stepside 4x4 i just replaced the engen in it and was driveing it for about 2 weeks then the fuel pump goes out,ive put 2 good pumps in the truck and cant get neather to pump once i get the tank back up into the truck does anyone know whats up? pluss when i do have the tank on the ground the only way it will pump then is when im cranking the engen. ive almost rebuilt this truck and realy tired of puting money in it thanks for the help

ok just tryed fixing all grounds on truck i found one that was unhooked but didnt know where it went but hooked it to the block and still no go it came from the firewall anunder that block of wires thats bolted on passengers side also put a ground on ground wire going to fuel pump and no go then ran a wire to hot side and truck fired right up so can i put a wire from there to the fuse box or will it be pumping to much? this truck has the 350 tbi in it it has the throatle body on it

ok i just fixed mine try spliceing into the ground wire and running a wire to the frame thats what just fixed mine

Yikes, in the 3 hours this thread was opened (at 4:51am), you have vixed your own problem already?

I was going to suggest the pump ground wire as I know they can have issues.

that was it now i got to figure out how to keep it in place on the wire i have no sotering iron here and it also fixed my speedomitor and gas hand