Engine/Transmission (1998.5 - 2002) Yet another!! dead Lift pump, less than 1,000 miles on it!

[John - K5AWO]

My boy, PJ, is about fit to be tied. !@#$%^ His 98. 5 CTD is dead again...



He calls me this evening a couple hours ago. He is cruising down the road about 45 mph when it all of a sudden it started running ragged and then just died.



He had a fuel pressure guage dangling from the fuel filter, so he popped the hood, bumped the starter and went back to look at the guage. ZERO... .



Brand new pump, used about 3 weeks. Now he is all worried, and I am too, that the brand new VP44 took a nasty hit. (Bob W. , say a prayer for him)



We are hoping that it was a sudden catastrophic failure on the lift pump and minimal VP44 hurt inflicted...



He would have had a dash mounted fuel pressure guage installed, but it was in my truck on the way to his house at the very time he called me. Talk about bad luck



Tomorrow he is calling Cummins and Freightliner to see who has the best price. Its' gotta be running by tomorrow night.

 

[dresslered]

Brand new pump, used about 3 weeks.

If the pump is really brand new, they come with a one-year warrantee, so you would at least be entitled to a free new pump. As I am sure that you are already aware, the underhood guage is only good at reading pressure at idle. It's the WOT pressures that will provide the good feedback as to the status of your lift pump. Perhaps it was bad right out of the box? Hope you get things resolved and the VP44 hangs in there. I have actually heard of several people driving many miles without pressure, and they are still on the original VP44.



Also, you might want to check if the electrical connector is still making good connection. This has been the culprit in the past as well.

 

[rblomquist]

Agree with above in that you guys need to read the pressure while going down the road. When he bumped the starter could he hear the pump? Sometimes when I bump my starter the LP gauge will read for a second or 2 then go to zero. I posted about this a few months ago and others had the same issue. When running though, it always read good pressure.



I wonder if there's an electrical problem somewhere in the scheme of things i. e. bad connector etc.



As for the VP, if it was hurt in because the LP was weak or failing for that short amount of time, with that small amount of load, I'd say it was probably a weak/bad VP44 from the factory.



Take your time guys and look at all the potentials before going to the worst-case scenario.



Good luck

 

[mhenon]

Lift pumps????

Why is that a lift pump can supply 10 or 12 psi, at an idle, yet when you put your foot into it and the VP44 is actually "sucking" fuel through the lift pump... it fails. Wouldn't it seem logical that it would fail the other way around... when you force it to build a head of pressure... like at an idle???

Maybe I'm thinking about this wrong but something doesn't make sense with this lift pump thing. Imaging a pump, any pump, with an inlet hose in a bucket of fuel and an out-let hose going into another bucket. Now you take your vise-grips and pinch the out-let line until a nice high pressure builds... say 10 or 12 psi. And the pump can handle this all day long. But, as soon as you take the vise grips off the out-let line and let the fuel run freely... the pump fails. That shouldn't happen.

Is there some way the VP44 is sucking "too' much fuel through the lift pump. . causing it to fail... because if that isn't the case... I'm lost on this.

I'm betting that "some" of these lift pump failures are a partially plug screen in the fuel tank. This would be like asking the lift pump to suck fuel through a pin hole. If the volume isn't to great... it can supply it. But ask it for a large volume. . like WOT... and it bogs down and fails. This then, leaves the whole job to the VP44... which is also over-worked and fails.

Somebody help me out with this if I'm way off base.



Mike

 

[dresslered]

Mike, the 'critical' specification that we are trying to monitor with the lift pump is the amount of fuel flow. As a first-order approximation, this pressure is directly related to fuel flow. As the demand for fuel from the engine increases, the pressure will drop as the lift pump starts to limit (if the lift pump can supply the need, the pressure should not change). Since pressure is much easier for us to measure than flow, this is the parameter that we monitor. In your case of the hose and vise grips, once the vice grips are removed, the pump should move tremendous amounts of fluid while still maintaining the proper pressure (i. e. the pump works much harder).

 

[Bob4x4]

mhenon ,

Part of the test for any fuel pump,includes measuring restriction on the inlet side of the pump. This is done with a vacuum gauge. On the Dodge it is very simple to do because of the handy quick connect fitting before the lift pump.





Bob

 

[Forrest Nearing]

I'm assuming the engine/injection pump is still under warranty, right? otherwise he wouldn't have reinstalled such a failure prone lift pump, right?



an aftermarket lift pump setup should be the "first thing" done to a 24v, the same way the KDP is the "first thing" done to a 12v... that's all there is to it IMHO.



Forrest

 

[John - K5AWO]

Status so far...

QUOTES STRIPPED.....

=============

If the pump is really brand new, they come with a one-year warrantee, ..... I have actually heard of several people driving many miles without pressure, and they are still on the original VP44.



Also, you might want to check if the electrical connector is still making good connection. This has been the culprit in the past as well.

=============

I wonder if there's an electrical problem somewhere in the scheme of things i. e. bad connector etc.



As for the VP, if it was hurt in because the LP was weak or failing for that short amount of time, with that small amount of load, I'd say it was probably a weak/bad VP44 from the factory.



Take your time guys and look at all the potentials before going to the worst-case scenario.

===============

I'm assuming the engine/injection pump is still under warranty, right? otherwise he wouldn't have reinstalled such a failure prone lift pump, right?

===============



WARRANTEE: Unfortunately, he bought it thru eBay. It appeared to be new, box was still sealed.



ELECTRICAL CONNECTIONS: These are brand new, we made them ourselves using 12 ga. Molex snap connectors with the proper Molex tool. Pump was not running last night. He had it towed home. Too late to get into it. Will be checking all out at 3:30 this afternoon.



Pump was moved to the tank and mounted on the frame. The only "issue" if it is one, and I don't think it is, we mounted the pump upside down to make the IN/OUT fittings inline with the fuel line. That way we didn't need to make u-turns or use rubber hose.



VP-44 FAILURE SHORT TERM: I asked PJ this morning how long it was between the first indication of trouble and shut-down. He said no more than 15 seconds max. So, my theory is, the lift pump simply locked up (or electrically failed), the VP44 tried to suck fuel thru the dead lift pump, stuttered a few seconds and starved for fuel and the engine died. I personally can't see that the VP44 should have been damaged in that short of a time period.



We are going to get the new FP guage installed tonight and double check everything. PJ is pretty sure the pump is dead because with it frame mounted he can normally hear it in the cab when engine if off, key on. Since he was out of cab checking for pressure and crawled under the truck looking for leaks and didn't hear it run..... it just about has to be dead, short of a failure in the wiring harness or ECM circuit which I doubt.

 

[YEEHAW]

Thats a bummer - Mine is working fine still. I haven't got the gauge on yet, but I check the pressure periodically under the hood.



Good luck

 

[GeorgeW]

mhenon,



I don't think you are off base at all. In fact, I think you are right on the money. The LP is driven by an electric motor and therefore its fuel delivery is independent of engine speed or load. It is, of course dependent on receiving the correct voltage. The injection pump (I think) is dependent on demand. SO, if the LP delivers at least 10 psi at idle (when it is working the hardest) it will deliver sufficent fuel for a stock engine. If the engine is not stock then that becomes a different matter.



Naturally, as the injection pump draws more fuel under laod, the LP outlet pressure will fall. This does not indicate a failed LP.



GeorgeW

 

[RCone]

I suppose the inlet screen on the fuel tank could be clogged (it is very fine and probably could be removed all together without consequence). However, then if that were the case why by putting on a new Carter would the fuel pressure come right back up? That was my case and that indicates to me that it was the LP, not a clogged inlet.



PS. The warranty on a new 3990105 from Cummins Northwest is unlimited mileage, 6 mos.

 

[John - K5AWO]

I suppose the inlet screen on the fuel tank could be clogged (it is very fine and probably could be removed all together without consequence). However, then if that were the case why by putting on a new Carter would the fuel pressure come right back up?

PS. The warranty on a new 3990105 from Cummins Northwest is unlimited mileage, 6 mos.

In PJ's case, the fuel tank was off at the same time the VP44 & lift pump were off. He installed a new tank screen module because the fuel quanity guage was SNAFU, and still is even though a new sender is in the tank. More troubleshooting to follow on that one.



I just got off the phone, a new 3990105 cost $138. xx out the door from the parts house, he's headed home now. A 1 hour ride on his '85 Honda Goldwing.



That parts house don't know it yet, but that new pump he just bought is going to have a terrible death in about 5 or 6 weeks :-laf and then at least he will have a spare under the seat at "half-price".



For myself, I bought a Holley Blue pump. When my 3990105 lift pump dies (org eqp) , it is going to be junked and the Holley installed as a pusher. End of Story.

 

[justinp20012500]

Man!!! What bad luck. I am still running on the original LP. I don't see less then 4 psi WOT and 15 at idle. I bet the VP is fine. I hope he didn't leave feed back yet...

 

[AKAMAC]

John, I've mentioned this before but never got a concrete answer. My new LP is stamped with "This side down" on the motor housing. This may be for cooling purposes. Mike

 

[John - K5AWO]

Just called PJ and he is looking at the new pump as I type this... . AND YES, the new pump does indeed have the words "This side down" on it.



He looked at the way he has the failed pump mounted and it is opposite to the way it was intended to go.



We can only surmise then that the pump is very sensitive as to its' orientation to the world of gravity. Does that make for a grave situation?

 

[dcochran]

The Final LP Solution

http://www.koengineering.com/



I don't think too many people actually read a lot of these posts. The problem has been addressed and fixed. I keep reading over and over again about the same old problems answered with the same old fixes. The real answer to the lift pump problems is in the above link.

 

[John - K5AWO]

http:/[COLOR=Navy]/www.koengineering.com/



I don't think too many people actually read a lot of these posts. The problem has been addressed and fixed. [/COLOR]

I do believe that I have read just about all of the posts on the lift pump problems, and I am well aware of the K. O. rasp system. Cost was the primary motivating factor with just moving the factory pump to the frame.



The K. O. rasp system is very new and expensive. A fact that just won't fly with PJ's situation right now, or mine for that matter. The fact of the matter is, the majority of these pumps do run a very long time without giving any trouble. We do hear of the bad ones on TDR because we are a group with common interests and we like to talk about what we do and what has occurred to us.



Neither PJ or myself will ever do much in the way of bombing our trucks. We both do plan on the Marco ECM upgrade, but not much if anything beyond that. neither one of us can afford to upgrade the 47RE slush box so we will be limited as to how much additional power we can upgrade too.



As for folks not reading all of the posts that have gone before... . I would say that that might just be true for 3/4s of the readers. I would hazard a guess that most of us are off for a spell, stop for a few minuttes and hit the "what's new" menu tab and take a look at what is happening "today". Go back and read all that has transpired since the last time we were on? not enough time in the day for that if you are an employed individual. I am in a situation where I can hit the TDR forum atbout 8 times a day for a few minutes at a time. Even at that, I probably only read about ten percent of the posts. I am selective and read what is pertinent to my truck, and, what is happening to the newer trucks. Interest in the 1st gen trucks is mild, but not alluring.



When we make posts or statements of "fact", we need to bear in mind that TDR members run the gamut of folks who think dropping $45,000 on a new rig is nothing, mere pocket change. The other end of that scale is the hourly paid fellow (gal) who is proud to just be able to obtain a well used CTD Dodge.

I'm somewhere in the middle of that scale, and not too high up on it at that. Well paid for what I do, but damn sure not able to justify 100's of dollars on fancy fuel systems.



The bad lift pump situation may have a good "fix", but for most of us, it is just a fanciful dream of "I wish".



Most of us will continue to muddle along with the factory stuff. PJ and I are very close. I offer him what I have learned by hard knocks and what I read. But I sure don't "tell" him what to do.



If reading about an "old problem" bothers some of us, well, we have the option to "not read" those posts. Just go on and read something else. But for all who have obtained their CTD ride recently, and that happens to include PJ and myself..... well, it is not so "old hat".



A fresh problem that appears today is a valid current issue. I don't remember making any statements in the original post that we were "wringing our hands" and wondering what to do. we knew what had to be done (get it fixed fast & now) because that truck has to make money, not just sit around like a flower on the wall.



Sorry for the long reply... . but that just happened to hit a nerve. Soapbox closed.



I just got another call from PJ about two minutes ago... Less pleased than he was last night. Installed the new lift pump (filled with oil) and turned on the key. Lots of noise for a little bit, but no pressure on the guage, then the pump quit. don't know why yet, it's 10:30 and 0400 hrs comes too fast. Time for bed.

 

[Sticks]

Huh.



I've mounted my LP on the frame rail UPSIDE DOWN about 9 months ago. No problems yet, but hearing that there is a "This Side Down" stamp on it, I may have to make a new bracket.



I helped a buddy do his and we used a couple of 5" L brackets from Ace Hardware, drilled a new hole in each of the top legs, made a short strap to hold the third bolt on the LP across the top, and used the original holes to mount to the frame (drill and tap). Also mounted a couple of 1/4 NPT ball valves on both ends of the LP (makes it so nice for ease of change out, and a bonus security feature).



As for your sons problem, it definitely sounds like an electrical issue. Your son should have received a new pigtail with the new LP. I would make a new wire harness (on the LP end) and first run it straight to the battery to see if getting direct power runs the pump. If yes, then finish the harness and connect it to the OEM fitting and see if it works... Basically do the good ol electrical testing/trouble shooting.



NOTE: I am on the "Perfectly good pump, wrong location" side of the fence concerning our fuel supply system. 9 months of a relocated LP (upside down) with 1/2" fuel lines all the way from the tank to the LP and no problems other than fluctuating fuel pressure that was cured by a quick servicing of the LP impeller and vane assembly. 14. 5# idle, 13. 5 highway, 11. 5 WOT, with an Edge EZ and stage II injectors.

 

[John - K5AWO]

Sticks,



You and I are on the same page with the electrical issue.



When I talked with PJ last night we discussed the wiring possiblity. He was in a hurry as it was so late in the night and just plugged in the new pump and gave it the "bump test" so it would pressure up the system.



We're going to give it a thorough check out this afternoon and be sure the power to the pump is good. At least now he has a warrantee to utiliize. Downside is the hour long trip into town it get it replaced.

 

[John - K5AWO]

It Is Fixed!! Ya Hoo

Well PJ had a stroke of luck. MDI Helicopter sent him into town this morning for parts to fix some of their stuff. He made sure that the first stop just happened to go by the parts counter for Cummins parts.



Traded in the old pump (ya hafta pay for a new pump! Then IF Cummins agrees the old one is bad, they refund your money).



Got the new pump on his truck with a new bracket he fabbed up so it sits "right side up". Purged the air out of the line and it fired right up.



Got all of his power back and the transmission is shifting great. He is tickled pink. New pump is putting out 18 psi at idle, so it should be good to go. That is the same as my pump does.



Well, hope all enjoyed the story. At least it ended with a good feeling.



John