leeboy

I now have a electronic gauge on one side of the fuel filter and a manual one on the other. So, once in a while, my electronic gauge reads 15psi, then after a while it might go down to 4, then back up to 13. Once it goes down to 4, if i turn the truck on and off, its back to 15 psi. The crummy thing is, when the electronic gauge is down to 3-4 psi, the manual one reads the same. I was hoping it was a electronic sending unit...but now im convinced its my lift pump acting all wonky. I cant afford $500 for a FASS , is a stock replacement one ok?

slim51015

Is the electronic gauge pre or post filter?

george7941

The internal pressure relief valve in the LP is shot and the LP has to be replaced, no other choice. The shot relief valve causes these wild pressure fluctuations.

To avoid this in the future and to ensure much longer life for the stock LP, just install a bypass pressure regulator (Simflo regulator available from Vulcan Performance for $38). Set the regulator to 12psi, that is all that the VP needs. This avoids the constant activation of the internal pressure relief and its consequent malfunction. Your stock pump will last for years and you won't have to spend $500 on a Fass.

hawkdiesel1

does this happen at random times? from what you have written it looks that way. I had this problem in my 01, it still does it and I have a fass. it's probably, like you said some sensor acting out. because i would be driving along and the fuel pressure would drop arbitrarily, and then rise again.

TOM R

I just had this on mine, I went to the airtex pump with the vulcan bigline kit and the frame relocation kit works great 20 psi

jentas

My pos electronic gauge fluctuated like that even with my airdog installed, but there really wasn't a problem with the fuel supply. The mechanical gauge showed that it was just a problem with the electronic one. My mechanical gauge has been rock solid for a while now, and the fuel pressure barely even moves under wot.

I'd really try to save money for a quality system like the airdog or fass if you plan on keeping the truck for any period of time. The raptor's also supposed to be excellent and is quite a bit cheaper.

I went through 2 stock lift pumps in less than a year, and had a spare in the toolbox with me, before upgrading to the airdog. The cost of those lift pumps is pretty close to what I ended up spending on the airdog. Plus, if I didn't catch the dead lift pumps, it would have been at least a grand for a new vp.

leeboy

I have the Electronic sensor in the fuel filter ( lid) port that is closest to the block. The manual one is farthest from the block. Im sure its the LP, cause they both read the same. When one goes down, the other goes down. I could see if the elctronic one was reading nothin and the manual reading 13 still...but both read the same.

jentas

Could it possibly be a loose connection and air getting into the system? Otherwise, what george7941 said; lift pump is about dead.

That pressure regulator sure is a great idea for pulsations from the vp, but what about the heat and excessive vibrations in the stock location that will lead to a decreased lifespan? Plus there's still all the flow restrictions in the stock setup. So, of course you could get another stock lift pump with a pressure regulator (or one of the other cheaper alternatives--holley blue...etc), but you still would want to get a big line relocation kit.

Even with a new replacement style lift pump, relocation kit, pressure regulator, and needle valve or snubber for the gauge, I'd personally still have a backup pump in the truck to switch out on the side of the road.

Sure, $500 is a lot of money. But when I think about the cost of the alternatives, plus all the extra worrying, the airdog is so worth the money.

leeboy

"Sure, $500 is a lot of money. But when I think about the cost of the alternatives, plus all the extra worrying, the airdog is so worth the money"

Good point, does anyone of those fancy LP's bolt into stock location or do they all get relocated?

jentas

The airdog kit replaced everything from the fuel tank to the inlet on the vp44, and all the fittings and fuel line are larger to provide the least amount of fuel flow restriction. They get mounted on the frame rail. The fass is very similar.

2 carter lift pumps, a big line relocation kit, and a pressure regulator must be at least $400. And you're still going to have all that cavitation because you won't be getting pure fuel.

I'm not trying to sell the things, I just wish I knew all the benefits of alternative fuel supply systems before I wasted a lot of money trying to fix something that's really poorly designed to begin with.

I feel lucky that my original vp44 is still surviving after the stock lift pump failures. Hopefully it'll go a lot longer running with the airdog and 2 stroke oil in the fuel.

leeboy

I wish i had the $500....Maybe i can get another year out of a stock one.....Any other soultions that bolt in stock place?

dodgediesel

You need a 1/8" pressure snubber to stabilize it. Worked very well on my 01 and it was about $15.00..

RUSSELLEE22

Hello, Fass now make a direct replacment pump at a great price. 269.00

leeboy

"FASS direct replacemnt"

I heard, im panicking to try and find one in Canada...