Rough running after sump swap to Fass

[Impalanator]

Hi all,
We bought a 2001 with a 5.9 Cummins. It had a beans diesel sump and we wanted to replace it with a Fass sump. It already had a Fass titanium pump. I contacted Fass because the return fitting was only 3/8” and the new sump is 1/2”. They sent me a fitting, a new spring and a new ball. We replaced all the old Fass fuel lines with new Fass FL-1002 1/2” fuel line.

We got everything installed, primed the Fass pump by loosening the water filter (xws) then tightening it after the tone changes on the motor.

We cracked the 3 injectors and primed the vp44. The truck idles, but it doesn’t go above 1,000 rpm, it sputters. Our fuel pressure gauge is reading 15 psi, but it is bouncing around erratically and I don’t remember it doing that in the past.

Thinking the vp44 might have failed, I tried unplugging it but the truck doesn’t ever start with it unplugged. It runs exactly the same if I unplug the Fass motor or leave it plugged in. The Fass system has been unprimed for a few weeks while we were on vacation and waiting for the Fass parts.

Any idea on this one? Do I need to spray WD-40 in the pump since it has been sitting so long unprimed (that is in the installation manual).

Thanks,
Ed

 

[Impalanator]

Update question. Would having the filters on backwards cause this?

the Napa filters that were on it originally, the particulate filter was on the left and the water separator was on the right. The manual for this case system says to put the water separator on the right, but the picture on the filters and this video Fass stent me says to have the water separator on the left.

https://www.youtube.com/watch?v=lpuNbRQTQdI

The new filters Fass sent me were the xws-3002 and the pf-3001.

 

[Impalanator]

Ok, the filters are correct, looks like they switched the filters with the new filter models. The truck is getting the following codes (it had no check engine light on before the install):
P0500
P1693
P1694

Thanks,
Ed