Engine/Transmission (1998.5 - 2002) another liftpump/pressure ?

[BWall]

Installed fuel pressure guage today as per instructions from Geno's at the VP 44 schrader valve, so down stream of fuel filter, filter changed 1400 miles ago. Readings 8-10lbs at idle and dropped as low as 4lbs under acceleration. Am I correct in thinking the lift pump is on its way out? What pressures are we looking for at this point of the system?

Would like some input from all you gearheads in the know on what fuel pump set-up would be best for my application. 2001 HO 3/4ton QC LB with Banks power pac system and exhaust brake. Primary use is hauling Eagle Cap camper aproximately 3700lbs and 16' tandem wheel enclosed trailer approximately 5000lbs when loaded with toys.

I don't need more power I just want reliability and durability. I was thinking a FASS 95 gph pump located down by the fuel tank. Whats the deal with the oversized fuel lines is it worth it? Can I yank the stock lift pump and disregard electrical connections and just wire the FASS into key on power source?

Do I need special bracket to mount FASS or can just attach to inside of frame back by the gas tank?

Thanks for your input.



Bill

 

[RAJohnson]

Bill Welcome to the TDR.



I would recommend at least 5-7psi at the VP as a minimum. I replaced my OEM LP when it was going to 4psi at WOT with no load. So if your towing and have a heavy load I would replace with a FASS, like I did. I personally went with the complete FASS system filters and all. A new fass will come with all the fittings, larger fuel line and mounting bracket's needed. When you install the FASS complete system you will need to unplug your OEM LP wiring and couple to the wiring provided with the FASS. There wiring extends your existing wiring back to where the new pump and filters will be located, so it will operate the same as your stock set up. The one option you will have that is not mentioned very often is whether or not you want to keep your OEM FF/Heater for cold weather. I have mine still in line, I went from the FASS with there new fuel hose to the inlet of the OEM FF and then from the output of the OEM FF to the VP with there larger fuel line. I tapped my fuel pressure gauge in to the output of the OEM FF with the use of a tapped banjo bolt. Hope this helps with your question and decision making.



Rob

 

[MikePowers]

I had almost identical pressures bout a year ago when I put in my guage. I used vulcan bigline kit with relocating LP. Now at Idle my truck has 12 psi and WOT it never goes down under 9 psi. Had it on there for a year now and this is the stock LP (hard to beleive I know) I just have an edge EZ, and a few other misc mods. I recently purchased a used LP for $20 on e-bay to use for a spare. Relocating the LP makes it a 5 min job to swap out LP in case of failure. FASS would be nice, but the kit is a cheap alternative and has standed the test of time (20K now)for me. Hope I don't start anything with this, last time I mention I have a stock origional LP with 80K on it, I got called a liar. #@$%!

 

[keimmmo]

Your pressure is about what I had before upgrading to bigger lines and fittings... kind of a home brew Vulcan kit. I now have plenty of pressure!



One question would be at what altitude do you live? I live at 6000 ft above sea level. I gain 2 psi across the board on fuel pressure when I drop down to sea level. This is CONSISTENT after dozens of times going up and down in altitude!!!



Steve Keim

 

[BWall]

My altitude is 5000'. Can't get FASS 95gph pump immediately so I am going to mount a pusher pump, probably carter back by the tank for now and see what happens hopefully it works as we plan on camping during presidents day weekend.



Thanks for the input.



Bill

 

[keimmmo]

I run the factory lift pump relocated just in front of the fuel tank and big lines with drilled out fittings. The truck has 137k on it and is on the second lift pump. The first one ran about 80k. At 6000 feet, it idles at about 14 and never drops below 10. I just do not see the reason for the FASS or other aftermarket systems. They are fairly expensive and have not solved ALL problems. The relocated pump is easy to change... not that I have to change it that often. And, I have factory parts, not something special, if I NEED to buy parts.



I ran a booster pump for a while. It gave me about 25 psi at idle. After a few months, I developed a hard start problem when hot. Removing the booster and just relocating the factory pump solved the problem. Two pumps are more complicated... and have more chances for failure. I like the simplicity of the relocated factory pump with big fittings and lines. Extra pumps WILL fail. Fittings and lines are a pretty permanent fix!



I can not stress enough that no matter what pump you use, the factory lines and banjo fittings are too restrictive even for a stock truck!!! Just changing the lines and fittings gave me an extra 2 psi at idle and 4 psi at WOT... with the same factory pump!!! I recommend you spend your money for lines and fittings instead of fancy pumps!



Steve Keim

 

[pz1]

how did you drill the fittings and is this a vulcan relocation pump system.

 

[keimmmo]

I was not aware of a kit existing to relocate the pump when I did mine about 3 years ago. I made a bracket out of scraps of metal and mounted the pump just ahead of the fuel tank. I have replaced the stock mounting bolts in the top of the pump with longer studs so I could mount the pump in rubber... eliminating most of the noise usually associated with the relocated pump.



I went to a store here in Mexico specializing in fittings and bought all my fittings. I use straight fittings now instead of banjo bolts. I noticed some of them had fairly small center holes, so I used my drill press to drill them out. Everything is now minimum 5/16 ID... even bigger where possible. I plumbed everything in 3/8 high pressure rubber hose, eliminating the steel lines. It took a couple of days to get everything made and rounded up, but as I remember, it cost under $50.



The factory line from the fuel filter to the VP is only 1/4 inch ID... and runs through banjo fittings to boot!!! How in the world they expect to feed even a stock motor through that tiny line is beyond me!!!



Steve Keim

 

[keimmmo]

Afterthought...

I did not use a Vulcan kit. I don't think they even existed when I relocated my pump. However, I have seen them and they do pretty well the same thing I have done. I spent less money, but far more time, by making my own system. The Vulcan kit is pretty much "plug and play" for a reasonable price. It would be a GREAT alternative in my opinion!!!



Steve Keim

 

[BWall]

Put Carter 4601e back by the tank mounted on the frame pushing through the stock lift pump this past weekend fuel pressure 22lbs at idle and does not drop below 15 under WOT with camper on and trailer hooked up. I plan on carrying a spare pump, filter just in case.

 

[CHornsby]

Put Carter 4601e back by the tank mounted on the frame pushing through the stock lift pump this past weekend fuel pressure 22lbs at idle and does not drop below 15 under WOT with camper on and trailer hooked up. I plan on carrying a spare pump, filter just in case.

Isn't that too much pressure? I heard not to go above 18 or something like that.

 

[rweis]

Brett Williams of II (Industrial Injection) has a post that the Bosch specs are 13. 5 input psi.



If you deviate off that then a diaphram (I think in the vane pump section) comes into play. There are seals on the diaphram and the seals are designed to flex +-. 5mm which equates to about no more than 4 psi +-. More flex than that and the seals start wearing (psi not within limits) prematurly and when the seals go the VP44 goes.



Look up Brett's post. Good post and information.



Bob Weis