Let's start out with my truck (2001 2500 5.9 Cummins) is stock. I and two of my friends have added a low pressure light to our trucks. One is a 99' he put his on the top of the fuel filter housing. Mine and the 02' are mounted as the fuel line goes into the VP44. We took out the fitting with the air bleeding valve and replaced it with a bango bolt that we drilled and tapped for 1/8" NPT. This is where we put our switch. (Cole Hersee part# 8606) This is wired to a small flashing light mounted in the dash. (Light is from an alarm system). When you turn the key on they flash. When you start the truck the flashing stops. The 99' now has a SuperChip programmer. He can not make his light flash even at WOT. The 02' has a Hiperteck programmer and will flash only at WOT. My 01' stock started to make the light flicker at random. I replaced the lift pump with a Alliant Power pump (#AP4943048) made by Carter. All three trucks have the same pump all installed within a couple of weeks. I have also replaced my fuel filter and thought the switch may be bad and replaced it as well. Now I have a didgial pressurre guage hooked to a meter. The pump will make 12 PSI at cranking. 10 PSI at idle and drops to around 7 PSI under normal driving. At WOT it drops to 2 PSI. Fuel Transfer Pump Kit-Cummins ISB engine equipped with VP44 Injection Pump-replaces Cummins Part Numbers 3990082, 3990105, 4932707, & 4935730. This pump is equipped with an internal bypass circuit that allows fuel to be drawn with less restriction in the event of an inoperable transfer pump. The kit also includes four banjo gaskets. This is on the box for the pump. WTF do I do now? Is the pump any good?

BB

 

im pretty sure that cummins says not to go below 10 psi. it will damage the vp44. around 14-16 is ideal. other guys on here will help you out, thats all i know though.

 

I wouldn't spend too much money on it, not so fast...

Before you installed that other pump, did the truck seem to run like it is supposed to? Was there any excessive smoke, and if so, what color was it?

Do you have some sort of specification on what the fuel pressure should be AND where it should be taken?

That other truck had your sensor mounted in the filter housing, and yours was mounted in another location--Do you think, perhaps, that's why the two trucks are getting different pressures?

It just seems to me like you are "chasing the magic dragon" here and possibly wasting money.

 

I don't know anything on the pump but best thing to do is get a fuel system like fass and air dog. They work and have added filtration. But it does sound like your new pump can't keep up. I would say all the trucks you mention need a fuel pressure gauge and a fuel system. I did the holley blue for a while but they just don't last.

 

Before I put the new pump on the truck would smoke a little grey on cold mornings. Other than that almost no smoke ever.

The 02' and mine have the sensors in the same locations.

BB

 

as mentioned, id get something like an air dog or fass...it is a nice assurance and it also lets you have room to upgrade......get that pump on and go from there...2psi at wot is much too low

 

Can anyone tell me what a stock 5.9 has for fuel pressure?

Correct me if I am wrong. We are looking for flow not pressure. As long as we have a possative pressure at WOT the VP44 is not being harmed?????

 

Well you could hook a flow meter up,or you could just go by pressures the way the rest of us do.
Mine is not stock,and it runs 15psi at anything over idle,it's about 14psi at idle.

 

This is not the correct banjo. You want the one coming from the fuel filter and does NOT have an air bleed. The air bleed side is the overflow valve. Basically, it's on the backside of the pressure circuit.

Dave

 

This is the line coming from the center of the bottom of the filter housing. Is this correct?

BB