I installed a fuel pump on my 2002 GMC Sonome engine 4 cyl. It started righd not startet up. But, after driven 2 miles, stalled out and died. Since then I could start only after taking out pump out of tank and reinstalled. Oil pressure is more than 40 PSI. I can not find any voltage from terminal.. I put a hotwire (jumper) from 87 terminal to 30 Terminal in fuel pump relay terminal, still no juice. I put a wire from batter to straight to pump . The new pump made noise . Still could not start. In this morning I put a jumper from 87 terminal to pump. I managed the engine running. I could start without jumper about 5 times. While the engine running, I decided to take my truck to road test. Whiel the engine running, I was gathering some tools and equipment for in case of broke down, the engine shut off. Why does my truck do this? I need help, please.

My friend has 1999 Sonoma with a similar problem. We have been trying fix what we thought was a bad fuel pump but when we removed the pump and reconnected it outside the tank it worked good for 2-3 seconds until the relay timed out. Then we reinstalled the pump in the tank and the truck started up with no problem and ran for a few miles and stalled the next day with the same symptoms. We get voltage in and out of the fuel pump relay but maybe no voltage to the pump. It took many hours to drop the tank and reinstall it in the garage with floor jacks so we don't want to do that again just to test the voltage at the wire harness connectors on top of the fuel tank. It is also a lot of work to remove the bed so how did you test the voltage at the fuel pump? Did you test it at the test jumper between the relay and the pump? Which wire at the test plug is the pump wire and which is the fuel gauge wire? Maybe the wire harness is bad? Other online forums suggested the problem could be a loose ground wire behind the bed but there are several plugs back there and i don't know which one is for the fuel pump or tank ground.

check the oil pressure sensor,

Fuel regulater ! Follow fuel line its after fuel filter underneath should be just before line goes up to injecters .