Starting off this truck sat for about 5 years before I came to possess it. I started with an oil change and a basic tune up. But quickly found out the fuel pump wasn't sending fuel to the motor. I tried to trace the wiring back but couldn't follow it. The pump has power just not much. The relay won't contact unless I put a spike tester in the sender slot I'm new to fixing stuff and I have no idea. Anyone that can help please. The truck has a 4.3 tbi swap from the 2.8 tbi I believe. The relay has 12 volta running to it. But won't contact. It's been replaced twice. The fuel pump is only receiving around 4 volts at the connector and it's not enough to kick the pump on the truck runs if we dump fuel down it's throat but I can't seem to get the pump to turn on to keep the fuel constant

 

Check voltage at purge connector and bring up the battery voltage charge battery first check battery for left of it's life span left ..do that first get a good power source wich is the battery..

 

There should be a Fuel Pump test connector located on the firewall. It is a small connector that breaks out of the wire harness. Apply battery voltage directly to the connector. It should latch the relay and apply voltage to the pump. Also, make sure that the ground wire for the pump is not frayed or broken and has a good ground to the frame. .Test the wire for continuity from the relay to the fuel pump connector with a multi meter and a long test lead. Swap the two relays on the fender with each other to verify that the relay is not faulty.