Good afternoon, I put a titanium fass lift pump along with a Fleece sureflo sending unit on my 2001 pickup about a year and a half ago. It’s been flawless for a few thousand miles. I had been noticing some slow starts when warm. Not bad just a few more revolutions than what was normal. I put some NAPA cross referenced fuel filters on because I didn’t have FASS replacements and didn’t have the time to wait . I started to take a trip recently and fuel pressure dropped significantly. I got the truck home and parked it for a month . I wasn’t real confident about the NAPA filters so i replaced with the direct replacement FASS filters. Test drove the truck for an hour or so and all seemed fine. Today it did the same thing again. I had gotten 17-19 psi at idle and 15-17 WOT. Today it dropped to 15 idle and drops significantly at WOT.

I talked to tech support at FASS and he mentioned something about a valve in the VP 44 might be a problem. Now when I turn the key on PSI jumps to 17 and drops to zero momentarily when I start the pick up. I’m in the process of putting a mechanical gauge in line to verify that the brand new auto meter pillar gauges are not the problem. Does this sound like a VP44 problem? Truck only has a 160000 miles, but I assume VP44 and everything beyond is original equipment .

Thanks, Kevin

Edited December 29, 2025Dec 29 by kbf98520

Got back on this issue today. I have replaced OFV valve. Im not confident this has fixed anything. I test drove the pickup and psi’s are 19 WOT to 23 at idle. This is not at all consistent with psi’s prior to this issue. Prior to this issue I had 17-19 consistently. I am going to continue driving this thing locally fully anticipating it to fail again….. ?

Plugged pump return . Flow into bucket 16psi ,into tank 23 psi. I get to drop the tank again . I’m so excited…….🙄

55 minutes ago, kbf98520 said:

Plugged pump return . Flow into bucket 16psi ,into tank 23 psi. I get to drop the tank again

Can you give more detail as to what this is about. I am not sure what it or how to interpret what you did.

Thanks for the update.

• John

1 hour ago, Tractorman said:

Can you give more detail as to what this is about. I am not sure what it or how to interpret what you did.

Thanks for the update.

• John

When I ran it today I had 23psi at idle. That’s way more pressure than I had when the pump was new so I disconnected the return to tank and ran it into a bucket. 15 -16 psi at idle. That tells me there is a restriction in the return circuit. Going to drop the tank and figure out what is going on on

43 minutes ago, kbf98520 said:

When I ran it today I had 23psi at idle. That’s way more pressure than I had when the pump was new so I disconnected the return to tank and ran it into a bucket. 15 -16 psi at idle.

So, are you saying that this "return to tank" is fuel return from the FASS lift pump, not the VP44? Just want to understand correctly what you are saying. If this is the case, it would seem that there could be a restriction in the return fuel line from the FASS lift pump.

• John

Yes return from pump