Well, I went to a little car show in town yesterday and had a good time. The truck ran great all day until i was on my way home and it just lost fuel pressure. I got out and checked fuel pump and it was running but, i had no fuel pressure. I tried tapping on fuel pump and nothing. my limited knowledge tells me either fuel pump or fuel filter. The truck eventually started and i went on home. Would replace fuel pump but it is brand new but then again so is filter. any suggestions?

 

Wait, did you install an electric fuel pump? You said you could hear it running, but with no fuel pressure the truck wouldnt be.

 

If it started back up, then I would suspect a marginal vapor lock situation first. This could include dirt in the tank that is fouling the fuel line inlet; a gas cap that is not venting properly; a fuel filter that's almost plugged up, or a true vapor lock in the fuel line - caused by heat on it, or a rubber tube that is being sucked in.

Any rubber hose over 3 inches in length has to go. Try replacing the gas cap and fuel filter. Then, start looking at dirt in the tank (maybe something large like a piece of gasket sealer), then the rest before replacing the pump.

 

yes, I installed a new pump and filter. and no the truck wasnt running only the pump. I think iam going to check the filter and check clearance to my exhaust , I know in 1 spot its about 4 inches away may need to reroute.

 

I've had this problem with two different vehicles. Once it was a piece of floating sealant someone had tried to use on the sending unit that had freed itself and was floating around the tank. Occassionally it would get caught on the fuel line inlet and plug it. As soon as the fuel suction was gone it would float off on it's merry way and the truck would start again - and run - until it got sucked in again.

The other time, it was the gas cap. It wasn't venting and there was a vapor lock in the tank.

I'd check that filter too. With a new pump, you may be pulling lots of stuff out of the tank that was previously just sitting.

 

With an electric pump, vapor lock is really pretty rare. 4" is plenty of clearance. What's the status of your gas tank -- original or new? Which fuel pump are you using? The Facet type are famous for overheating their electronics and stopping until they cool down, even tho they will make noise like they are "running". Doesn't just happen in summer either, I had one in a Jeep/360 and it did it in dead of winter.

 

It is an msd electric pump and the tank is new. I guess i will check the filter and then check the tank for any debris. I did near a noise when it cleared couldnt really tell where the noise came from but pressure did come up when i heard it. hopefully i can find the culpret.

 

What about a regulator? Which one are you using? Doesn't sound like you've got a dirty system. Cheap regulators can spazz out, and that would fit with a running pump but no gas.

 

the regulator came with the efi system so im not sure of the brand. The only thing that makes me lean towards the fuel pump or filter is the sound i heard just before i got pressure. It seemed to come from the back of the truck.

 

Sorry, I didn't realize this was an EFI system -- OEM? or aftermarket? That makes vapor lock even less likely IMO, if it's a 35 - 50 psi system.

 

Its an aftermarket system. Yeah, 45 psi.

 

I may be wrong but I was thinking a EFI system has two fuel pumps, one on the rail which is high pressure and one in the tank which is low pressure.

 

It's not typical to have 2 pumps, but there may be some application out there that does.

 

In your thread you mention that you checked the filter. There should be two of them a pre-filter before the pump and one after the pump. TYSK.