Is it the fuel Pump or A relay?

[jrawson78]

I have been working on my truck which is a 1994 ram 3500 with the 8.0 V-10 magnum. The Fuel Pump stopped working and sending pressure to the fuel rail. I have since put two pumps one used and one new in it and primed them blew out the lines and made sure that it was pushing fuel before trying to start it. Last night I was driving around after I got the new pump in and it died again acting like it was out of fuel. I got out and checked the fuel rail pressure valve and it is at it again. No fuel pressure. is this a relay problem or something more serious? Please help if you can lol I am goin nuts with out my truck.

[jdl]

How long since a tune-up? Any applicable codes? You can check those yourself. When it stalls does it restart quickly?

If you suspect a fuel pump issue, you use a gage and check fuel pressure. Next, you have to check for voltage and ground for the pump motor, engine cranking, when problem is ongoing.

When the problem occurs, are you missing anything besides fuel, how about spark at the plugs?

[jrawson78]

the fuel pump seems really weak for some reason. Idk why it is a brand new one and this is the second one in the last to weeks. The ground and all the hot wires are good according to my voltage meter. I am really stumped on it. I have good spark and it turns over great just not enough pressure getting to the rail. then it cuts out compleatley like the pump is bad and stops pusshing fuel all together.

[danielsatur]

1) Rolled the fuel pump relay with another of same type in your fuse box.
2) What about the fuel filter?

[jrawson78]

Its a non servicable in the tank pump with filter on the bottome and it looked in good shape.

[jdl]

What was the voltage reading at the fuel pump connector? The initial prime doesn't give you enough time to check, you need to have helper crank it.

Can you check amp draw?