Fuel Pump Bad?

[Trenton]

A little backstory. Just yesterday I dropped my truck off for an alignment. Well I got a call saying "hey I think you mint have ran out of gas" which was impossible, I only had about 160 miles on that tank. So when I went to go pick it up, I called roadside assistance for some fuel and even after a few more gallons it didn't start. I pushed the little valve in the service port and only a little fuel came out. It couldn't have been the 55 psi worth of fuel it needs. I can hear the fuel pump running. Even after swapping relays it does the same thing. Is it possible for a fuel pump to still run but not provide enough fuel pressure to start the engine?
Truck is a '98 K3500 CCLB SRW with the 5.7L Vortec.

 

[Eveready]

How many miles? If you are not getting much pressure the pump would be a suspect. If you are well over 100 K since the last one, that is another vote. A fuel pressure test with a gauge will probably be the decider. I hope that others with more experience than me will add their thoughts. Someone will know a quick test that should give you the answer.

 

[evilunclegrimace]

Dead head the pump and see if it will build pressure you might have a faulty fuel pressure regulator

 

[PlayingWithTBI]

Or a plugged filter.

 

[454cid]

My 454 will quit at about 10psi, and that's when it's already running. The 350 needs more pressure since it uses that goofy spider assembly. I would think it very possible to have a pump "running" that wouldn't allow the engine to start.

 

[Trenton]

Or a plugged filter.

I wouldn't think so, it's a fairly new Wix filter.

 

[Trenton]

Dead head the pump and see if it will build pressure you might have a faulty fuel pressure regulator

What do you mean by dead head?

 

[kennythewelder]

A 5.7L Vortec, needs over 60 PSI to start. Anything less than that, and the truck will be hard to start. You could poor a little gas down the throttle body, and see if it fires up. And yes, the fuel pump will run, nut not put out enough pressure to start the truck. Once the engine starts, it takes less pressure to keep it running. You can rent a fuel pressure tester @ autozone. Over 60 PSI before starting. Once started, it will fall into the mid 50s. Also when replacing the FP, only use AC Delco, or Delphi pumps. Anything else will not hold up.

 

[Trenton]

How many miles? If you are not getting much pressure the pump would be a suspect. If you are well over 100 K since the last one, that is another vote. A fuel pressure test with a gauge will probably be the decider. I hope that others with more experience than me will add their thoughts. Someone will know a quick test that should give you the answer.

The truck has 258k on it and the pump has supposedly been changed before. I would use a fuel pressure gauge if i had access to one. None of the auto part stores around here do tool rental and there's no harbor freight within 50 miles of me.

 

[Eveready]

It was probably changed around 150 or so which means it could easily be due again. I don't know what to tell you re how to test without a gauge. It might be worth taking it in to a shop to get a diagnosis if you know a competent shop in your area.