I have a 1994 4.3 Gmc jimmy 4WD. Last time I drove it, it slowly started to have less and less power. I had to feather the gas pedal to get moving from a stop. Any time I gave more gas it would fall on its face. When I parked it, it wouldnt start. I noticed that the fuel pump wasnt kicking on like it always does when I first turn the key to the on position. Now I have swapped the Fuel pump relay with still no pump. I have tested the voltage at the pump connection in the back and I only get 8 volts. Before I change the pump I need to know if that is sufficient voltage to run the pump (I think 12 volts should be there). If not what would cause a voltage drop here.

Any help would be appreciated

 

Try running a hot wire back to your fuel pump and see what that does, the voltage is to low. If with the hot wire it works OK, you will know it either a relay or wiring.

 

Or just bypass the pump relay under the hood. You will find a small female plug near your pump relay, feed that baby 12v from your battery 3 feet away to bypass the relay. I think its got a pink wire with a plug that is just hanging there not hooked up to anything. If it doesnt come on now, you need a pump or wiring inspection around the gastank. Start with checking your grounds always, it could be someone that stupid.

 

I did the hot wire from the battery to the pump and got nothing. I pulled the tank and swapped in a new pump, so I am back up and running. Thanks for the help. I just wanted to make sure it was the pump before I went through with swapping it. I ended up swapping in a new filter and relay for good measure, and my friend donated the pump which was new in the box waiting on a Grand National build that he abandoned. So now the Truck is part Buick! LOL

Thanks again