87 gmc dual tank 5.7l tbi short bed truck.well i can get it started using the fuel pump priming wire.when i unhook it it will stay running.when i go to restart it it just turns over and that's it.i can hear the fuel pump run when i turn the key on.help it has new fuel pumps in both tanks,i changed the fuel pump relay also.any help would be so much appreciated thank you

 

could see if any fault codes are stored in the ECM-jumper a+b on the diagnostic plug under the dash and watch the "check engine"light flash sequences for the codes.I don't recall if these trucks have a wire from the crank terminal on the starter to the ECM to tell the ECM a start attempt is being made-if there is a break in that wire,could cause hard starting ?

 

 

thank you very much for reply back,but i think i have it fig out .i bypassed the porting vlv for the two tanks.then tried to start it and got no fuel at the inj's.so i tried it by plugging in a power wire on the fuel pump priming wire.an unhooked both fuel lines to the tbi.could hear fuel pump running but no fuel at the supply line.so i think i blew the hose on the fuel pump outlet in the tank or the pump gears are shot.my money is on the first option.will keep you posted.now i am gonna have to look at a wiring diagram to see if the starter sends power to the ecm to signal it a start attempt is being made.again thank you very much for your reply back.

 

got it was a bad fuel pump or a blow hose between fuel pump and sending unit.fired right up.thank you everybody for your help.