Does anyone know for sure if fuel will flow thru a OEM lift pump (2nd Gen) with the OEM LP not running, as in no electrical connection to it, with this fuel being pumped from another Lift pump,be it a Carter or Walbro or other from a by the tank location. In other words if one was running 2 LPs, one at the OEM location and one at the tank location and something went wrong with the one at the OEM location,will the second add on pump by the tank be able to pump fuel thru the OEM LP?

 

It will flow, but the VP is working hard to get any fuel.

Kinda like running a marathon while wearing a snorkel. You'll not die-- just wish you could.

 

I have diconnected one pump several times and so far every single time it works w/o any noticeable side effects......HOWEVER I could see where under the right orientation of the vanes in the dead pump it might block the flow, AND if the rear pump was to go out it would be a real nasty load on the front. The problem all but goes away when using 2 pump though as they do not work as hard.

 

Then I should be alright in leaving the original OEM LP right were it is but not run it,just pump fuel thru it with a Walbro down by the tank,I would put a bypass around the Walbro with a ball valve,that way if the Walbro should ever quit,just turn the valve,start up the OEM LP and keep on truckin.

 

Hi Dodge Demon
Why disconnect the OEM LP ?
If you are going to fit a extra pump,let them both run,they will not have to work so hard.

 

Well heres what you do. Unhook your old fuel lines before the stock fuel pump. Clamp a line between the factory pump and the new pump. Put power to the new pump and see if it pumps fuel thrue the factory pump. If it does then your answer is solved.
I would hate to see you go thrue the hassle of going either way and finding out the other way worked fine or better. Tyr it your self and let us know how it works out.

 

I wanna know too

 

When I hooked up my fuel pressure gauge after a good few months of owning this truck (not to mention the previous owner....) fuel pressure was 1 PSI at idle and 0 PSI at any speed Drove to work everyday clueless ...

 

Did you ever have to change your VP44 Inj. pump yet?

 

I have worked on literally dozens of trucks that were like that, probably for many months.

 

Not yet. Truck has 185k miles and I bought it at 160k.

 

Good Luck. You are going to need it.