I wonder if my lift pump isn't up to par. I installed the Max Flow system per instructions and a fuel pressure guage at the same time. When I turn the key to on, the lift pump cycles and I briefly see 10PSI. After starting the truck, I see 10 PSI again. Then, down the road at WOT, (that's what you do after starting the truck, right?) ;D pressure goes to 5.5-6 PSI. > Cruise is at 8-9 PSI.

I have a PM3 Comp set on level 3, but it shouldn't affect the idle pressure, right? I don't have any other fueling modifications. I thought I was supposed to see 15 PSI when at idle. Is this indicative of lift pump failure?

thanks. brandon.

 

Your lift pump is weak. You should see cruise pressure around 12+

 

Brandon,

It sounds as though your lift is done, but before you go replacing it, disconnect the line on the fuel filter inlet and inspect it for any contamination. We've seen small pieces of rubber (Probably from decaying filling station pump hoses) gather at the fuel filter inlet and block flow. Also, check your fuel filter. If both of these are fine, you're off to Cummins for a new lift pump.

Rod

 

Thanks guys!

I was hoping that wasn't the case, but I suppose it's an excuse to get a FASS system. I have a 45 mile old fuel filter in it and I didn't see any foreign articles when I put the line kit on. Unfortunately, I just bought this truck so I'm not sure how long it's been run this way. If this has been happening for the last 155K miles, is the pressure low enough to think about starting an IRA account for my VP44?

brandon.

 

I doubt anyone can say for certain when it comes to a VP44 pump.

My truck still has the factory installed VP pump. It has seen 0 psi at the track more than once. It now has a 100,000 miles on the clock and still running.