Engine/Transmission (1998.5 - 2002) Best way to fix lift pump

[SHobbs]

No need to feel stupid. Not sure on the technical stuff but I do know that AN fittings have been widely used in aircraft applications. AN will give a better flow over the stock banjo fittings. They are easier to use and most utilize push lock fittings which do not require hose clamps. Since you are getting a Vulcan L. P give Eric a call at Vulcan Performance he can set you up with everything you need.



Since you are planning on dropping the tank ask Eric about a draw straw. The draw straw will give you a larger pick up tube in the tank and allow you to use 3/8 or 1/2" line all the way to the VP44.

 

[Fishin Guide]

A-N Fittings to the best of my knowledge are a universal agreed fitting for the Air Force and Navy.



They are 37 degree. Some JIC sizes will interchange or adapt for use in low pressure environments.



If you go with the FASS or AirDog, you are going to get a draw tube for the tank. Only if you use the filterless versions would a Draw Straw be an appropriate purchase.



Make sure all lines are diesel rated. We have veggie oil/ bio rated lines that far exceed the durability of the traditional air line (blue) included with the aftermarket kits.



Even if a stock style pump is retained, going to to a draw tube with -8 line on the suction side will greatly help the pump draw fuel. Relocation kits are available that include all the fittings, harness, mounting brackets and pumps.



Dave

 

[blacksheepdiesel]

SMikel,

No need for a draw straw with an AirDog, even with the 1/2" hose. I have 295,000 miles on my AirDog with the factory tank innards and absolutely no issues with sucking fuel from the tank.

If you really want the AirDog do it now instead of the Vulcan. PM for dealer contact.

Godspeed,
Trent

 

[Fishin Guide]

I disagree on the draw tube with the AirDog or Fass for that matter.



Many of the later 2nd gens trucks have a far too restrictive module. Some trucks got the '99 style and it flows MUCH better. And even this module has it's quirks. But to not install a part that comes with the kit does not make sense.



It is well documented that most trucks pull a vacuum with the factory module even with the factory fuel system. I recommend a draw tube with ALL fuel system upgrades. It is worth every penny and has no negative effects.



All bypass pumps move far more volume through the module than the non bypass types. The Raptors and HPFP are a bit better in this regard. As they are "on demand" style pumps. But even in many cases a draw tube is not only recommended, but required.



Dave

 

[blacksheepdiesel]

Fishin Guide,

I agree that a draw straw is desirable and certainly has no negative effects. It is possible, however, to install an AirDog without one and have have great results because I have done so for the past 295,000 miles. If the factory module has something wrong with it that causes a greater restriction than when new then it absolutely must be replaced with a draw straw. Also, if an in tank lift pump has been installed it must be removed and a draw straw installed before any out of tank pump can be used. My guess is that is one reason why AirDog started including the straw in their kits because so many people are installing an AirDog after finding that their in tank pump is completely insufficient for even a stock truck.

Yes, install the draw straw that comes with the kit. But if you don't have time or resources to drop the tank then run the AirDog without it and see how well it works. If need be the straw can be installed later, unless there is an in tank pump and then the straw is a must. AirDog was designed to fuel high performance trucks utilizing the factory module.

Godspeed,
Trent

 

[Fishin Guide]

Here's how I look at it.



My own '02. Put a cam and 12V lift pump in. Had 20 psi @ WOT45 psi @ idle. The truck would have driven just fine and did at those pressures. No loss of mileage or performance.



When I was having some HP issues I wondered if my fuel system was at fault. It was pulling a huge vacuum on the suction side. Since I had -8 lines, I knew it was in the module. After tons of testing and diagnosis, I got the very first draw straw ever built in my truck. WOT pressures went to 37 psi same idle pressures.



Now, that truck would have run just fine. But a mechanical pump is physically tougher internally than the aftermarket electric pumps. My point to all this is it's a very cheap and often necessary mod. I know this as I have diagnosed too many trucks to count with aftermarket fuel systems. The biggest enemy is sucking air and that's primarily due to the pump trying to pull more volume that the module will allow.



While your specific truck and others don't seem to have this issue, I would recommend installing a vacuum gauge on the suction side of your system. You may find a problem that you did not know existed.



One thing I have learned from lowering the vacuum threshold is that aeration and cavitation are almost cut to nil if the pump is mounted in the correct location. Fuel is heavy. And the bigger the lines, the harder it is to move. This is just a little thing that helps most guys.



By all means, do what is best for your install. But all the bypass pumps move much more volume over the same time than any of the non-bypass pumps. It's just the way they are constructed. I know that AirDog was not shipping a draw tube with the 100gph unit. But now I see them in every kit. Something must have changed at the manufacturing level to encourage them to do this. I have spoken top Charlie and many others about this very issue. I don't think most manufacturers buy the factory tank and modules and actually experiment. I did. And as soon as I can get my act together, I'll have some videos concerning the running out of fuel thing.



Dave

 

[DCruger]

New question

I have a stock 1999 2500 6 speed 4. 11 gears

everything is stock except

exhaust break after the turbo

a fuel filter by-pass switch ( makes changing fuel filters easier)

i am also running amsoil

and running fuel from PEMEX

I have a 90 gallon tank also in back.

The L. P. is stock on the engine block.

I have notice that the W. 0. T. Pressure dropping to 9lbs it was at 13 or so when i first bought the truck 2 years ago when it had 30k not it has 85k



I have a 10,000lb horse trailer that i use to haul my horse around with. that is the only real towing i do. I do not drive over 55 well maybe 60. but do not drive over 2k on the tach. if i do millage goes way down.



any suggestions on L. P.



never going to race and if i cannot get fuel in mexico will get a smart car and leave the truck hooked up to trailer at the ranch.

thanks ahead for any and all help



DC

 

[DCreed]

I have a stock 1999 2500 6 speed 4. 11 gears

everything is stock except

exhaust break after the turbo

a fuel filter by-pass switch ( makes changing fuel filters easier)

i am also running amsoil

and running fuel from PEMEX

I have a 90 gallon tank also in back.

The L. P. is stock on the engine block.

I have notice that the W. 0. T. Pressure dropping to 9lbs it was at 13 or so when i first bought the truck 2 years ago when it had 30k not it has 85k



I have a 10,000lb horse trailer that i use to haul my horse around with. that is the only real towing i do. I do not drive over 55 well maybe 60. but do not drive over 2k on the tach. if i do millage goes way down.



any suggestions on L. P.



never going to race and if i cannot get fuel in mexico will get a smart car and leave the truck hooked up to trailer at the ranch.

thanks ahead for any and all help



DC

great post! If it aint broke...

you already have a gauge and as long as you STAY above 5psi, you're golden. lot of fellas just carry a spare LP and filter, just in case.

Happy Trails!!