Hi guys, I think I may need a new lift pump, but not too sure.
When I got the truck the fuel pressure was sitting at a vey low 27 lbs. I shimmed it up to 65 and it is still there, but now I can only drive a mile or so before she starts to chug and lose power. Even the idle is rough after that. It will come back after sitting and idling for a while, but then I only get another mile or 2.
At first I though plugged filter. Nope, It's good. Plugged screen between the filter bowl and FPR? Nope. Clean as a whistle. I went back through the system and even went so far as to check the screens in the fuel tanks. Both good. I checked the fuses and they're all good. Checked the oil level just in case. It's good too.
I read vwman80's post about his fuel pressure and thought maybe that's it. What do you guys think?
Sorry about the long post, just wanted to get everything out there. Thanks

 

Oh yeah, it sounds like it is dropping one cylinder at a time until it won't even pull itself along. No weird smoke or anything either.

 

Hey guys, since this could kinda go along with my problem, can you explain to me what the lift pump does? Do the same job as the pressure pump. I hope thats not a stupid question?

 

That much I can answer. It just draws fuel up from the tanks and keeps the fuel rail charged up to the injectors. After that, the HPOP and the injector solenoids do the work.

 

Technically the pump does two functions, it draws fuel from the tank under low pressure and pumps it through the fuel filter, then pumps it at high pressure through the fuel passages in the heads.

 

Okay, I guess I was thinkin that the lift pump fed an injection pump, but not on a PSD.

 

My mistake. I should have figured that out when I looked at it. Not just 2 or 3 lines to the pump. Anyway, I got it changed and it's like a new truck. Shoulda done this last year when I first noticed low fuel pressure. Live and learn.