Hello XXXXXXXX,
Year 1987
Silvarado Suburban
Miles 172,967
Master A.S.E Automotive technician
A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
I have replaced a million of these electric fuel pumps,it's almost like they are designed to fail.The way this system works is when you turn the key on,the ECM sends a message to the fuel pump relay for 2 seconds & primes the line w/pressure.When the engine starts & oil pressure comes up voltage is changed to the oil pressure switch & this circuit feeds the pump as long as the engine has oil pressure & ECM signal.
Draining the fuel tank with a stand alone pump needs to be done before removing the tank.In the shop,I unbolt the bed (8 bolts),raise the vehicle about head high ,put 2 jack stands under the bed rails & lower the truck which in turn raises the front of the bed.When there is enough room I step in & remove the sender assembly without removing the tank.If this is your problem & you replace the pump .go with the fuel sender assembly.This unit has pump & level sensor complete.