My fix for the weak link lift pump problem

[Whit]

All 24 valve owners are aware of the weak link of the oem lift pump, The lift pump supplies fuel from the tank to the VP-44 and also circulates an excess amount thru the VP for cooling and lubricity of the pump before returning the fuel back to the tank. many many owners have tried to correct the problem , some with continued failure and some with success, many have added a pusher pump and it is my believe that this only adds twice as many pumps for failure, I know a pusher pump is being used by alot of CTD owners with success but this mod was not for me, I also know that the new FASS system has so far had great reviews by folks actually using them but the initial cost to me is expensive, but if the FASS will prevent the loss of a VP-44 then it would be worth it, I will admitt that if I were still using my oem tank as a feed source I too would have a FASS in service. Here is an alternative system I have had in place for about 2 years and so far have had great luck with, If you run an auxillary tank in the bed of your truck you should consider this system as it has proven for me.


I dont run a lift pump and I dont want one


When I say I dont have a lift pump that is exactly what I mean, I took my oem lift pump and moved it back on the frame under my in-bed fueltank where fuel with head pressure of 1 pound is being supplied to the suction side of my pump....................................my pump no longer lifts fuel at all and is now considered a delivery pump!

NO pump likes to pull a vacumn but prefers a positive head pressure, the OEM setup is the problem, the pump is on a constant vacumn from pulling up to 2 feet and from up to 8 feet away, there is not a pump on the market that will survive this kind of application or punishment.

Here is what I have done to correct my OEM fuel delivery system. I purchased an auxillary inbed fuel tank, this is my MAIN supply to my delivery pump ( no longer a lift pump ) I have installed a ball valve at the bottom of the tank for maintenance purposes and 1/2" line to the pump, 1/2" line from the discharge of the OEM pump to the OEM filter housing in its original location and 1/2" line from the filter to the VP-44 and all banjos have been removed and replaced with -6an fittings.............................RESULTS ARE I now idle at 15 psi of pressure and cruze at any speed at 15 psi!!! and at wot I can only pull it down to 12 psi!!! As far as fuel usage from my Cummins I have 275 injectors and a comp box, the above stated readings are with the comp on 5x5. Before this mod my numbers were cruze 75 mph at 12 psi, WOT at 4-5 psi.I now use my OEM fuel tank as a storage and transfer tank.

Bottom line is if you dont want a lift pump than turn it into a supply pump.

Cheers, Kevin

 

[MUDDY]

me liken the idea kevin. makes sense. at wot goin from 4-5 psi to 12 psi. good improvement. also with factory undrbed tank used as a transfer tank the ability to keep inbed tank at higher level helps w/ cooling of the lp [now termed delivery pump] and the vp-44. movint the lp back and using inbed tank to have constant positive prssr would sure make the pump last much longer

dang good idea

i gotta figger where i gwine put my inbed fuel supply w/ cmpr on

 

[NAIL BENDER]

Originally posted by MUDDY

i gotta figger where i gwine put my inbed fuel supply w/ cmpr on

Whatever you do MUDDY, don't put it in the cab with you. Because, where would your kids sit?

 

[MUDDY]

hmmmmmmmmm,,,cld put it in frnt passngr seat,,,,,,,that way mean ol lady cant go wid me;p

cept for instalin gn hitch,,,,,,,,cld build tank 4'x8', 2 1/2 inches high as i space cmper up a bit to give more room above cab anyway. shld be over 50 gal

i just gotta remembr to NOT overfill it where it expands out vent on warm day when parkin in big k's drveway

 

[TPCDrafting]

Is it me or do you guys have to stop when you get to Muddy's posts and just watch for a while?

Couple questions Kev,
1 did ya fix the noise problem with the pump being away from the motor? I know you said all you needed was some rubber bushings on the mounts, but was wonderin' if that did it.
2 Did you also run that extra line from the far side of the tank to solve your gravity problem when the tank is low?
3 is there a way to mount the pump under the oem tank and accomplish the same results or would it become a ground clearance problem? How about an in tank pump?
Just some BS to keep the conversation going. I know you put a lot of time into this and I think it's the best idea yet.

 

[NAIL BENDER]

Originally posted by MUDDY
[
i just gotta remembr to NOT overfill it where it expands out vent on warm day when parkin in big k's drveway [/B]

Your parking in the dirt next time you are in town.

 

[Stoked]

I did the same thing on my 98. I removed the lift pump from its original location and mounted it on the frame rail next to and below the tank. I extended the wiring harness to plug back into the factory plug. Worked fine until the VP44 finally crapped the bed.

The "Pusher" pump system that Diesel Dynamics sells for the 3G trucks does the same thing. The factory lift pump is removed and replaced with a high volume pump mounted back by the tank and new lines to replace all factory lines and banjo fittings.

Why can't DC put the supply pump in the tank like all other fuel injected vehicles?

 

[Whit]

Originally posted by TPCDrafting
Is it me or do you guys have to stop when you get to Muddy's posts and just watch for a while?

Couple questions Kev,
1 did ya fix the noise problem with the pump being away from the motor? I know you said all you needed was some rubber bushings on the mounts, but was wonderin' if that did it.
2 Did you also run that extra line from the far side of the tank to solve your gravity problem when the tank is low?
3 is there a way to mount the pump under the oem tank and accomplish the same results or would it become a ground clearance problem? How about an in tank pump?
Just some BS to keep the conversation going. I know you put a lot of time into this and I think it's the best idea yet.

Tim good questions,
Yes I did rubber mount the pump and now I can barley hear it when I turn the key on, all it does is buzz now and when driving I cant hear it at all.
I also taped into the other side of my tank like we talked about and ran it to a Y at the suction of the pump, now I have ffed when in a curve or on a slope as well (my tank has no baffels in it)
I think you could mount a pump under the oem tank (ground clearence would be a problem) but you wouldnt have near the head pressure as with an inbed tank. I know that 27 inches of water column will make 1 psi of head pressure but I dont know how many inches it takes with diesel.

Cheers, Kevin

 

[caper]

Hey Muddy , can you change your avatar ??? I can't read your posts it destracts me too much. HE HE