Guys I need some advice. I filled up at a well respected truck stop in my area Monday morning. They also put Powerservice in their fuel. Anyway after the fill up I took off for work and was driving down the freeway and lost all fuel pressure. I got scared and started to pull over and FP came back to normal. So I kept going figuring maybe it was the gauge. It did this all the way to work. On the way home also. But on the way home the truck was surging a little, so I knew the gauge had to be right. Got home pulled the filter and it seemed fine, didnt appear to be gelled or dirty. I then added about 1/4 bottle of Howes lube and anti-gell. Then this moring on my way to work the same thing happened again. I turned around and nursed it home this time. Am I gelling up or???


Fuel Filter is fairly new, less than 7,000 miles as is the IP and Walbro lift pump.

Thanks for any help guys, Bret

 

Electric fuel pressure sender going south, or loose wire to the sending unit? Try verifying the problem with a mechanical pressure gauge.
-P

 

I also noticed that the fuel was real "cloudy" when I had the filter out.
I am in the process of trying to find a mech. gauge to check it. But I dont think the gauge is off, seeing as the truck started surging when I lost PSI. And stopped surging when PSI came back. But I will check to make sure I cover all bases. Is this new USLD fuel supposed to be cloudy?? This is my first diesel and I guess I never really looked at the fuel before. I know the older better fuel was more honey type colored.

 

I don't think it is supposed to be cloudy. Unless they saved money and put something other than powerservice into it... this is why I put my own in, to be always sure of it.
If it surged when pressure was dropping, I'd worry. Could be as simple as air leak but has to be pretty big for pressure sender to respond! For the lift pump, I always was concerned with Walbro pressure relief valve, and seeing people report 26+ psi from it going to the IP, which is designed to hold only 17 psi. This is why I am hesitant to go with Walbro as a package. What was your FP, by the way?
-P

 

It could also be your IP going bad. If the IP isn't working right it could cause that surging.

 

Fuel Pressure on the X-monitor was anywhere between 15 and 25 at idle. I could pull it down to 9-10 @WOT, this was before it started acting up.
I was able to rig up a mech. gauge, it was a steady 20psi @ idle. Cruise was about 18-20psi. WOT from a dead stop I can pull it down to 0psi. WOT at 45-55mph, it would only go down to 15 PSI. I changed the fuel filter, and that didnt improve anything.
I think was is possibly happening is;
1. My x-monitor is a POS.
2. I dont have the big line kit from the fuel filter housing to the VP-44, thus at WOT from a stand still, I am starving the VP for fuel through the little banjo bolts.

I know the truck was surging, it wasnt much at all, but I did feel it. The Smarty is on SW 9, which I dont run very often. Maybe thats causing the surge?
Ever since I got the X-monitor, I have yet to get steady FP reading like everyone else that uses analog gauges. I have also had problems with the Pyro on it to.
Is my guesses on what is happening sounding right to you guys or am I just trying to convince myself that its the X-monitors fault?
P.S. the walbro and vp-44 were both replaced in June and both are under warranty. The vp-44 is a reman from II.
I have acess to another ride for work the next couple days, so I will use that and try to get a mech. or a different electric FP gauge.
Thanks for the help so far fellas, Bret

 

I would trust the mechanical gauge over the x-monitor. In the electric sender there are things to fail, in the mech gauge - not really. This is the main argument people have against an electric gauge, despite the simpler installation and cleaner setup.
I don't see why you should be unhappy with the pressures you're getting. 10 psi wot = happy VP, from what I read. Zero psi is strange, I don't quite understand this one but wot from standing still is not exactly normal driving conditions, is it? But 10 psi is way within factory specs for lift pumps. I would not bother with a big line kit if I had such pressures.
I am not sure about the surging, but having a mech gauge as your indicator I would probably set the Smarty to a 5 or 7 and drive it to see if you feel it again. With a bulletproof system like Walbro, if the VP has decided to go the only way you can stop it is not to drive it - then what's the point of having it? I would drive and watch the FP with a less aggressive Smarty setting.
-P

 

I just got back from a little 20 mile trip. Main purpose was to watch FP. I literally beat the living crap outta this truck and the lowest I could pull the X-monitor down to was 12.5psi. So i dunno, maybe the darn electric sender was just having a bad couple of days. But it still doesnt explain the 0 psi with the mech. gauge at WOT. I know that is not normal driving, but I plan on adding a TST box in June, so I just wanna make sure the fuel system is soild. Thanks again, Bret

 

Update: I think the Walbro might be going south. I will keep this updated