Its one of the electrical ones. It has two post on the sending unit one that goes to the gauge, and one of a ground. I ran the ground to the battery and used their wiring harness for the wire to the gauge. Then coming from the back of the gauge included in this harness is a red wire for power when you turn the key on. A yellow wire for the constant power. A orange wire for the dimmer and another ground

 

wrong.


there would be negative pressure in the line or vacuum in the line from the injection pump pulling the fuel rather than the lift pump...

having less than 10psi while driving and running WOT is quite literally damaging your injection pump...

sure it can run like that for a while, but not for long...


what you fail to realize is that fuel is the ONLY lubrication and coolant for your injection pump...

it is just like running an engine with no oil pressure and zero coolant. sure it'll run, but not for long...

you need 14psi minimum to keep the vp44 adequately cooled down and 10psi MINIMUM to keep the pump within bosch runnin specs. 7spi is only spec for engine cranking, not engine running conditions...


I run 20psi idle and with maximum fueling at WOT it only drops to 16psi.

 

jigabop....... I got thinking about the Injection pump pulling the fuel and I agree with vacuum rather than pressure. WHS7221, I would suggest making sure the gauge is wired correctly if you are sure it is you may have a lift pump on its way out. Good luck!

 

I have had a couple of issues with my glowshift gauges, but with my fuel pressure gauge, when it had issues, it would go all the way up, not down.

on another note that nobody touched on here, your vp44 needs more than 12 psi before you are returning any fuel to the tank. if you are not returning fuel to the tank through your ip, then your ip is not getting the cooling it needs. The vp44 relies on excess fuel to keep it cool. if it overheats, it fails...

you always need more than 12 psi for your ip to last. keep in mind though, it doesn't tolerate any more than 25 psi

 

FASS DDRP Dodge Direct Replacement Pump - 98.5-02 Dodge Cummins
Any thoughts on this pump?

 

I have seen no evidence to back this up...

max input pressure is not documented anywhere by bosch.

high input pressures can cause hard to start issues, but I have seen people running 27psi to 30psi without issues.

I would be worried that seals might leak from the high pressures though but again it's all word of mouth, I have seen no documentation to support the theory.

now for the low pressure side we do have documented evidence from bosch and cummins showing specs.

13-14psi = overflow valve opening pressure 10psi = minimum operating pressure 7psi = minimum cranking pressure. all of which can be found in the cummins service manual. nowhere does it state maximum input pressure though.

to be safe though I run at 20psi input pressure and 16psi is as low as my pressure drops with the vp44 pushing so much fuel it actually sputters and falls on its face if I push it any harder (basically I'm sucking it dry with my injectors and wiretap fueling)