Engine/Transmission (1998.5 - 2002) Lift pumps...lets think outside the box

[Whitmore]

1st off there a a thousand posts on lift pump problems for the 24v rigs, that is the obvious pitfall and most troublesome area that we need to adress.



2nd lets NOT talk of the problems but lets concintrate on the FIX.



3RD the OEM system was destin for disaster before it ever hit the field. End of story, lets NOT try to re-work this crap set up.



4th I know that a 2nd pump is being used as a pusher also with some success but we are still reporting some failures of this setup, it has problems too.

A) you now have 2 pumps which makes thice as much potential for failure.

B) some setups also require a regulator because the 2nd pump has too much flow..... one more piece to dink with and added expence.



Pump school 101 says pumps work best with a positive pressure and not a vaccumn.



that being said lets look at pushing the fuel instead of pulling it!!!



proof has shown us with some success that moving the OEM crap pump closer to the tank has increased reliability, thus LESS vaccumn.



I want a system that has 0 vaccumn and nothing but positive head.



OK now how do we do that... ... . with our set up there are ONLY 2 possibilities



1) mount the pump below grade of the tank and feeding it from the bottom of the tank to give it that much desired possitive head, is this possible ??? yes. Is this right ??? NO... . WHY ???

A) the pump is now hanging low and is subject to being torn off.

B) the tap into the bottom of the tank is a risk for future problems.

C) You no have a system that is exposed to cold weather and evan treated diesel pumps better when warm or hot vs. cold.

A) your pump will be hanging low and we risk tearing it off



OK the other option is to mount pump in the tank... ..... I know I know Most of us have experienced this in the past and it aint pretty to have problems with this set up but please hear me out. IF we can find this pump being used with success on another application we will gain.

A) nothing but head pressure and 0 vaccumn

B)No exposure to the cold outdoor elements

C)No clearence problems for off roading or straddling objects on the highway.

D) no risk of bottom tap of the tank.

E) plenty of cooling from the mass supplied by the tank volumn.



IF we can find a pump that will deliver the specs we need it will be beautiful once installed... ... ... . what kind of specs???

A) 15 psi delivery. 20 would prolly be good too but most of us have 15 psi gages so that would require another up grade and besides CUMMINS has speced 15 psi deliery as being addiquate.

B) propper flow is needed, there has been much discussion of what is required in order to supply the fuel needed for the motor as well as excess fuel to circulate thru the vvp-44 for cooling and lubricity, which is the ultimate goal of an addiquate system. Flow is our concern not psi, the ONLY reason we monitor PSI is because it is to expensive to measure flow... ... YES we also do need to be concerened with PSI too a secondary measurment ! dont get me wrong here !

C) If we can find this pump we can install bigger hose to feed the system as well as give propper spillback to the vital components then back to the tank.

D) tank mounted pumps are exstreamly reliable if the DO NOT run out of fuel.



The ONLY problem I see with this setup is how do we use the existing tank for this in-tank application???



One other thing in case of breakdown, I have in the past lost a tank mounted pump ONLY because I ran it dry,but was able to splice the line on the frame and mount a pump and succesfully pull thru the tank pump. We could provide propper fittings to do a roadside fix and install the oem unit to get us in.



my question for other wrenchers, auto parts sales , or backyard mechanics is where can we find this kind of a pump over the counter???



Please constructivly disect all of the above and give pros and cons of the idea.



please NO war stories of the OEM crap unless it is conducive toward possitive information towards the FIX!!!

 

[Whitmore]

come on fellas

let er rip, I am tired of threads about lift pumps... ... lets fixer

 

[Pit Bull]

Originally posted by Whitmore



I want a system that has 0 vaccumn and nothing but positive head.

Sounds like something I could live with

 

[TxDieselKid]

A) 15 psi delivery. 20 would prolly be good too but most of us have 15 psi gages so that would require another up grade and besides CUMMINS has speced 15 psi deliery as being addiquate.

Now we do have boxes where we can tune the power, but does Cummins think 400-500 hp is addiquate? I would like the higher end of 20 psi during idle. 20psi during idle, maybe once in a while 15 under WOT with the box on "KILL" if ya know what I mean.



Sounds like your trying to find a pump you can put in the tank.



Andrew

 

[csutton7]

I punched a hole in the bottom of my tank for a 100% gravity feed system and yes if I do need to be mindful of stuff sticking up, but my plan is to build a skidplate for the fitting to prevent damage---my Aeromotive 1000 pump is mounted on the frame and on a bracket right in front of the tank that hangs below the frame about 1. 5", but I'm lifted 5" so I do have some leeway---pressure is between 16-18psi and never drops below 13psi no matter what---it's been on for 13 months and 12k miles with most of that city stop and go driving and numerous shutdowns and startups---chris

 

[Whitmore]

Chris

this is great news, I did not know that any one has done this. I am excited to here of you effort to fix and this setup is a good one dont get me wrong, you are going in the right direction,and your efforts are commendable to do something that no one else has tried.



now if we could just get the pump in the tank ... ... . JMO



thanks chris... ... ... ... ..... Kevin

 

[15w40]

I have been searching for a reliable pump to replace the Carter pump that came with our ISB. After testing the Carter pump in several different ways, I have been able to come up with a list of specifications for the replacement.



For a stock engine, or one only mildly bombed (VA or Edge EZ box) the lift pump must supply 95 gallons per hour, open flow and 45 gallons per hour @ 15 psi. If showerhead injectors and/or a major fueling box is added the requirement will increase. The pump should put out 120 gallons per hour, free flow and 58 gallons per hour @ 15 psi. At maximum engine RPM and pulling a load, these ratings should keep fuel pressure at the VP44 above the 8-psi minimum.



I have been searching for a one-pump solution to meet these requirements and have a life span of 6000 hours or 200K miles. I though I was on to something when I found a tank mounted lift pump made by Olympic Controls Corp. , but it only develops 7 psi of pressure. This pump is designed for government tactical vehicles and is reliable.



http://www.occorp.com/?page=Pumps





I am also looking into a pump made by Belgoes that will deliver 120 gallons per hour with a claimed life of 10,000 hours. This pump is still in development and will be available in November. Belgoes makes smaller pumps now but they are not enough for the ISB. Here is a link to the Belgoes pumps.



http://www.fuelpolishing.com/cat213_1.htm



I believe there is an answer out there. It just may take some more time.

 

[JHansen]

I've been pondering this for a while Kevin-I may have even sent you a PM about it once-time erases all memories it seems . Here's what I've come up with... ... .



AFAICT from looking at the sending unit module that came out of my truck (to drill the hole for the Espar fuel pickup) it and a gasser fuel pump module are a straight swap. I have a fuel pump module for a V10 sitting in the basement now awaiting my attention-so many BOMBs, so little time! Looks like it'll be a straight swap-in for the diesel one.



The gasser engines use a returnless fuel system-the regulator is actually grommet-mounted into the top of the module. They run on a 30 # pressure rating IIRC which is too much in my opinion. It should be possible for a clever fella to take this regulator apart, clip the spring some to lower the pressure and make it into an adjustable regulator with a plate above the spring, a nut welded to the top cover, and an Allen screw pushing through to allow the spring tension to be varied. This may be a major PITA-quite possible a fella could adapt an external regulator easier and seal the largish hole in the top of the module.



It gets better too-there is a dip tube running to the module bottom that is identified as an auxiliary fuel pickup. Simple matter to extend it with hose down to the frame and cap it off for future use.



Of course this little job would require a little rewiring and repiping-but I believe it's easily in the realm of doable-just haven't had the time to get at it myself. Very soon though..... I am bumping into the supply wall now and soon I will be smashing through it!



2 questions that will require a guinea pig to answer though-1. Is the V10 pump robust enough to move enough fuel? The #'s I saw in a NAPA book looked OK-but the only real way to find out is to bite the bullet and give her a go. If it wasn't big enough I'm sure a handy fella could adapt one of the higher-volume intank pumps designed for Mustangs etc... -that should be OK! #2 is lifespan-as diesel is heavier than gasoline. Personally I believe the extra lubrication will extend the pump's life-but I also believe that the fuel gets hotter in our trucks than it does in a gasser because of the VP44 heat transfer. This issue is gonna take a little longer to figure out.....



You're not alone out there buddy... ..... drop me a PM if you wanna converse about it in real time and I'll give you my cell #.



Jason

 

[Whitmore]

sounds like you are onto something 15-40 is the Belgoes pump you are refering to intank or frame mounted?



you have supplied some great info towards a propper application that is WAY over due and has the potential to make many many Cummins owners very happy and trouble free



thanks and keep us up dated and if you need test vehicles



I am mad as heck of this oem poor poor design



15-40 your reasearch and commitment is commendable

 

[Big White Beast]

Just what I've heard.......

The stock filter set up regardless of lines will only flow 45 GPH. No matter what pump you come up with the filter needs to be addressed also.



I have a low pressure high volume pusher and it seems to have fixed my problem so far. Time will tell. A lot less cost and work. Dropping the tank and replumbing the fuel line is not something I would look forward to.



My 2¢ worth,



Garrett

 

[15w40]

Whitmore- The Belgoes pump would have to be mounted outside the fuel tank. When talking with the engineer who is developing the pump I learned that the pump would operate using a solenoid (plunger) and reed valves. This design allows the pump to be deadheaded for extended periods

of time without problems. There are no brushes to wear out and the number of parts is minimal. One problem I see with this design is that the fuel flow will not be continuous. If the pump is as reliable as they claim it may be worth a try. And by adding an accumulator to keep the pressure up as the solenoid returns from the pumping stroke the fuel pressure should remain as constant as the Carter rotary vane pump we have now.

 

[csutton7]

a year and half ago when I did my hole punching I looked into a in-tank pump setup, but couldn't find anything that I felt would do the job, so that's why I did the hole punching--it only hangs down 2" below the tank and it may be a little less--I have great expectations for this setup--and although my miles aren't numerous, starting and stopping the pump are usually a lot tougher on electronics than straight running--there was a thread that someone posted about using a military in-tank pump that was good for all fuels, but nothing ever happened or the guy is still trying to locate one---dropping the tank is not that bad--hardest thing is to get the big plastic nut to screw back on and to keep the sender clocked right--of course get it as empty as possible also----chris

 

[Whitmore]

more input

months ago while dinging off I stopped at the dealer and looked at a 1 ton with no box on it , I concentrated my looking at the big nut that holds all the stuff inside the tank, I would think that a guy could retro fit a fuel pump and lv sender from this hole , oh and also the return line, I think we could hang the pump off of a bracket from this hole kinda like the gassers do .

 

[Cummins Cowboy]

What would happen if you just took the whole tank w/in tank pump off another vehicle such as a v10 or other vehicle and mounted it to the truck connected the wires and hoses. don't some of these types of tanks also have return fuel coming into them.

 

[metal tech]

csutton7, Did you put any sort of metal stiffener inside or on the bottom of the tank to prevent cracking. I used to have plastic tanks on my GMC that developed cracks. Your setup using a -12 or so AN bulkhead fitting is probably the best solution for pos pressure feed. Those folks that have upgraded to Transfer Flow tanks may be able to get a Bung fitting welded to the bottom of the tank. I think that for "most" of us, the danger of driving off road and ripping off the fitting is not that big an issue. Driving over something on the hiway and having it kicked up at 70+ MPH is a good reason to get something under there to deflect it away from the fitting.



Al

 

[csutton7]

metal tech--simple answer is no I didn't rein force it--I don't think these things can crack as they are a two part system--kind of a clear/whitish inner plastic bonded to the black outer coating is the best way to describe it--just took the bulkhead fitting with the poly washers on the inside and outside and made a metal washer to go between the poly washer and the rim on the bulkhead to prevent it from pulling through and gooped her real good with some teflon sealant---you know you bring up a good point about kicking stuff up on the roads--guess I better move this skid plate up the list to be safe---Transfer Flow will not weld a bung--I asked last year --but maybve if you asked about a drain bung you might get lucky-too bad I thought of it now-anyway if they won't you could always do it yourself----chris

 

[Whitmore]

???

I am seriously considering using my aux tank to feed my lify and then using my oem tank to transfer to the aux = positive head to the lift

 

[AlFischer]

A question for a fluid dynamics expert: If a pump is mounted external to the tank and is at the level of the botom of the tank other than the restriction of the hose from tank to pump why would there be a vacuum? I remember my old high school physics experiment of two containers with a hose between them would equalize fluid levels.



Where I am coming from is that while I believe the in tank pump would be best it sounds impractical to locallly engineer such a setup. But a proper external pump, properly hosed, would deliver the results needed and at the same time not be a nightmare to deal with when (not if) it failed. Seems that all the in tank pump failures I have personally experienced we with a full tank. (my luck?) Have heard the same from others. Drove into a gas station and filled up. Car would not start. New pump fixed problem.