What causes low fuel pressure?

[clinker clint]

Well, I put a new piston pump in. Turck started out at 15lbs of pressure for the first day. 10lbs at WOT.

...lol, well I left the truck out in the sun and nowI only run 10lbs at idle and 5 at WOT. At least It's not dropping down to 0 anymore. I'd sure like to know why it does that. Wonder if it is something in the gauge??

I've got The dual fueler sump is still in the box. I'll get it in when I can.

[RCCUMMINS89]

It's picking up junk in the tank. Check the inlet screen on the lift pump.

[clinker clint]

I put an see-through, inline strainer just before the pump. It's till clear. I've dropped the tank twice in two years and it's been squeeky clean both times I've dropped it. I have also checked the screens inside the tank, both clean.

[RCCUMMINS89]

Have you checked the screen at the inlet of the lift pump? Next thing is to look for scoring in the cylinder of the lift pump.

Double check gauge accuracy?

[clinker clint]

The pump was new when I put it on a few days ago. I checked the screen when I hooked everything up. I have not double checked the accuracy of the gauge. Wouldn't it be a kick in the nuts if this was all a gauge problem???

[RCCUMMINS89]

Check the screen at the inlet of the lift pump again. If everything is new, and nothing is clogged.... it almost has to be the gauge.

[clinker clint]

Will do, thanks for your help!