pokapotato

Okay you can see my sig. I noticed on my control pod last night that when the road speed is over about 30 mph, my transfer pump is running around 17 psi. That is under normal driving conditions or if I get on it. The transfer pump seems to be doing what it is supposed to. The strange thing is when I come into a stop light my fuel pressure according to the control pod goes all over the map often going down to zero and then seems to do this while at the light. Once I pull out of the light and get up to about 30 mph the fuel pressure being read on the control pod comes back upto 17psi and is fine. I noticed this when I had about a 1/4 tank of fuel. Filled the tank up, with same result. Here is what I have confirmed visually. No electrical connection issues with the transfer pump, pump relay, pump fuse or control pod fuel pressure sending unit. Hoses are okay from the VP-44 up to the fuel module on the tank. I do still need to confirm the fuel pressure issue with a mechanical guage yet. My sending unit is right at the VP-44 inlet, FYI. If I do indeed see on antoher guage that I still have the problem I am suspecting something is going on in the tank with the fuel module (the fuel pickup). Great, now I get to drain 30 gallons of fuel so I can drop the tank by myself(: Has anyone else had a similar problem?

thellums

Not sure if the blue chip pump has an inlet screen, but mine did the same thing with my Glacier. Ended up being a dirty tank of fuel that was clogging the inlet screen on the pump.

sheriffav8r

A Fleetguard FF5079 before the lift pump is a good fix for ensuring semi-clean fuel to the LP. This is a 25 micron screen that runs about $13 or so from Cummins.

pokapotato

There is an inline filter befor the FASS transfer pump. If this was beginning to plug I would think that fuel pressure would be low all the time not just at lower road speeds. The trasfer pump never pumps faster or slower unless battery voltage changes, which battery voltage is not changing. Maybe I will change the inline filter before the transfer pump just for kicks and see if anything changes.

LongBlackRam

I had a similar problem that turned out to be a bad stock transfer pump. I swapped out the pump and the problem went away.

tx_2500

Time to replace your lift pump. I had a weird irradic FP reading and it just got worse over time. Better to do it now than get stuck somewhere with it showing a big fat 0.

pokapotato

Well I got a manual guage hooked up and ran the truck up. The manual gauge is dead steady at 18 psi while the control pod is reading all over the place. Either the fuel pressure sending unit is junk or there is and issue with the control pod. The wire is tight on the sending unit and there are no wire opens shorts or grounds. We'll see what Quadzilla wants to do with it. Just glad everything is okay.

PaulDaisy

I was going to say, it is probably a flaky sending unit. With a FASS you should have good stable pressure unless it is dead, in which case it would be zero all the time. Quad fuel pressure senders are known to have problems and I am not sure if there is a replacement unit that is proven stable yet.

98.5Hotrod

x2 what PaulDaisy said.

Diesel-Dan

MAN i will be glad when Quad comes out with a sending unit that holds up....i get at least a call a day on this.....

I would suggest running an Auto Meter Snubber #3279 to protect your sending unit.