Changing the fuel pump - 1991 GMC Sonoma

The fuel filter is part of the fuel pump, so if you are wanting to change the fuel filter, the fuel pump must be changed as well. The fuel pump is located in the fuel tank and the fuel tank would need to be dropped to remove the fuel pump.

In the under hood fuse / relay box . Fuse #48 15amp F/P - INJR , Relay # 18 fuel pump . GM Fuel Pump Relay Testing

Most likely the fuel pump is ok, but there is likely air in the fuel line that you need to bleed off under the hood.

It is possible that the fuel pump went bad, and the way to know is to check the fuel pressure (same place you bleed it under the hood). The fuel pump is in the tank, so it's a real pain to change.

you need to drop the fuel tank out of the bottom to change the pump

Believe its fuse 9 10 amp did you try jumping power to the pump?? check the ground

Yes you can just change the fuel pump, there are genuine and aftermarket options available, You need to remove the original pump from the cradle and this will allow you to confirm the size of the replacement pump.

George,
No simple diagram for changing the fuel pump. It is located inside the gas tank. The gas tank needs to be removed to change the pump. The pump is part of an assembly which consists of the pump, fuel gauge sender and pick up. You also need to change the fuel filter when you change the pump. It should take a professional mechanic about 3 hours to drain the fuel out of the tank, remove the tank, change the pump and fuel filter. Multiple the mechanic's time by whatever the repair shop charges per hour for labor. There are several different pump assemblies for the vehicle. Price depends on whether it's 2 or 4 doors and 2 or 4 wheel drive. Best guess is about $600 total.

Recalibrate to the PCM

Did you change the fuel filter? If not change it. Is the fuel pump actually running? Listen at the fuel filler with cap off while someone turns on the ignition without starting the engine. The pump should run for a few seconds. If not, check the fuse and fuel pump relay.

Have you sprayed brake cleaner in the intake to see if it will start, if it does then check the fuel pump fuses and the fuel relay, before changing the fuel pump make sure there is power to the fuel pump (test light works fine) always change the fuel filter when putting in a new fuel pump.