So the other day it got to -15 here and my tank was at about one quarter and I had a bunch of ice crystals in my fuel so it ugged my wix inline filter before the lift pump and I lost fuel pressure. After I fixed that it happened again yesterday and the temps were still cold. I stopped at a station and put 10 gallons of diesel in and the problem went away. I had fuel pressure again on my guage. Is it normal to have the fuel pressure read 70 while idle all the time? I had a problem where the pressure would jump to 100 randomly but I was told it was a bad fuel pressure sensor most likely so I ignored it well I replaced the fuel pressure return thing on the side of the fuel bowl with a stock one and I was at 60-65 psi all the time. Now I'm shooting back to the 70-80 range. Any ideas on what's going on? Plugged return line maybe? Or that return valve is acting up again? I'm going to drain the tank to get all the ice crystals out I'm not sure how that happened.

 

When the tank is low it can allow condensation to accumulate. A clogged / frozen/gelled return line can cause high fuel pressure.

 

My fuel pressure was high by 10 PSI the other day and it's been riding high by 5 PSI for weeks (near and below freezing here)... that's with the white bottle of Diesel Kleen in the tank. I about had a heart attack when I first saw this, because a jump in fuel pressure is one of the late symptoms of a loose injector. I have since learned the lower the temp, the higher the fuel pressure. I think that cold return line is a viable explanation for many 7.3Ls. I have the FRx, which returns warm fuel to the tank. Other than the mild rise in FP, I haven't seen any other symptoms from the cold weather... and this has been through very cold weather last year.

 

I'll see how it acts tomorrow. How does that FRx work? Noticeable difference? Worth adding to mine?! Ill try to get a video tomorrow of how the pressure fluctuates. I just want to make sure this is all normal. Thanks for the advice.

 

which fuel pressure gauge are you using?

 

Isspro EV2 gauges. I'll get a video up of it. It's 29 outside right now I leave it plugged in constantly so ill show a cold start then after it warms for a minute I'll drove it so you can see the psi changing frequently. It's been doing this for a while.

 

What I like about mine: It solves the dead-head issues. If you are in desperate need of a Hutch mod, the FRx can help with the cackle... but that's not why I have it.

 

I have Isspro gauges also, and the fuel pressure would peg do to a bad sending unit, actually it happened twice. Call them, they will send you a new one, their good like that.

 

This morning my fuel gauge said 55 when I started it then once it was warm I'm sitting at 65-66 psi not as high as I was. But here is a few videos I tried to run wide open a few times so you guys could see what's going on. I just don't want to damage anything.

 

 

My DiPricol fuel pressure gauge (in the cab) is @ 6 years old and lately is has been driving me batty. It always finds the worst time to start bouncing around making me think about my pump going or gelling. It's usually around zero dark -thirty, pulling the camper and /or cold as a witches nipple on Halloween when it starts bouncing around erratically. When I finally get the chance to pull over and pop the hood the fuel pressure gauge on the ITP regulated return is at 65 and steady. So I unplug the fuel pressure sensor on the back of the fuel bowl and plug it back and the in cab gauge goes back to working normal. A short? Bad sending unit? I don't know.........