Engine/Transmission (1998.5 - 2002) dodge replacing the lift pump with a pusher pump

[Dodge5256]

a few days ago my truck stared thowing a P1688 code. i took the truck to the dealer today and they told me that is was most likly coused by the lift pump failling. he said that since lift pump failure is so common on these trucks that they have made a kit that dealer are now instlling that replace the lift pump with a pusher pump that mounts by the fuel tank. Has any one else heard of this? if so could someone give me some more information about it, like who makes the pusher pump, and is it any good? any info is much appreatated.

 

[nps]

It doesn't mount by the tank - it mounts IN the tank. It is a replacement fuel module adapted from the 3rd gen fuel module. Those that have had the change report that the fuel pressure is low and can be pulled to near 0 levels at WOT - not an issue for the CR engines but not good for the VP44.



I was once an early proponent of it, but now I would not let the dealer put one in my truck. I'd go for the Carter pusher mounted outside the tank.

 

[Joe Mc]

Ditto what nps said. Don't let em do it!!! Plenty of kits to relocate your pump. a few sites check w/Rip first @ http://www.sourceautomotive.biz/



http://www.haisleymachine.com/ http://www.vulcanperformance.com/dieselperformance.html



Not affiliated w/any previously mentioned sites just MHO.

 

[jjordan1]

I had the same thing done to my truck. The problem as i see it is ,I only get 8 # pressure . I dont think that is enough to keep the VP 44 working. I sent to Vulcan Performance for larger fittings hopeing that i get more pressure. Talk w\ Eric @ Vulcan he can get you on the right track. Good Luck

 

[cyborg]

Dealer istalled the In-Tank on warranty, I'm going to add a pump in the stock location with bigger lines.

 

[David Wheeler]

In-tank pump

Well, I came to this forum this evening to ask the same question. I took my 2nd gen. in for a weak lift pump this morning. Was told this weekend it was at 4psi (idle) and 0 at anything above (verified). Anyway, I was surprised to find that the fuel filter was actually the culprit (was time for changing anyway) and the LP was fine (to be verified later). Boy will I hear about this from my technical buddies! Anyway, when I picked up the truck the diesel tech and I began a conversation. That's when he told me about the "in-the-tank" retrofit Dodge is now doing on all LP failures going forward. I was intrigued, but because my LP really wasn't dead, Chrysler would not authorize a replacement. BOY AM I FORTUNATE! Came home with the old LP and not heading for bigger problems as I now read! I guess the FASS system is still the best option! Thanks TDR!



David

 

[jelag]

I had put a helper pump on my truck... its an 04 but my story might help... .



The lift pump failed with a helper pump... . I thought that the helper pump, mounted at the tank would push fuel through the lift pump... it would not... . if the lift pump won't run there is no fuel supply. . I found this out 150 miles from home one afternoon... .



I did the change out... as my truck has had one lift pump failure before and is out of warranty... . so it now has the intank pump installed and we checked the fuel pressure... all seems to be fine... .



We also tried to suck fuel through the new tank mounted pump... thinking that we'd fire up the helper pump, and boost the pressure... . we found that if the new tank mounted pump is not working there is very little fuel we can draw from the tank... . this seems to be a catch 22... . so we're now running this truck like our 05, with just the pump in the tank... .



If it fails again... I'm going to take out the pump in the tank... . and run the helper pump only... . I was hoping that if it failed on the road... we'd at least be able to hook back up the helper pump and get home... . we just don't think we'll be able to do that... .



Just my thoughts on this... .

 

[jeepit]

My truck is at dealer with dead lift pump. It is a catch 22 here. If I get my own engine mounted lift pump I have to pay for labor and, heres the biggy, they may not warrant injector pump if I do this and VP44 fails down the road. If they put the in tank pump in then VP44 is warranted for the 100,000 mile mark. Damned if you do damned if you don't.

 

[nps]

If they put the in tank pump in then VP44 is warranted for the 100,000 mile mark. Damned if you do damned if you don't.

Or 5 years, which you should be hitting in about a year. On the other hand, a Cummins replacement LP is slightly more $ than the $100 deductible DC charges for the 5/100 Cummins Engine warranty. So if all that is replaced is the LP, then change out the factory one yourself with a Cummins replacement and then start the next catch 22 - hoping your VP fails before the warranty expires or hope that you got one of the good ones that will never fail. :-laf

 

[GWedekind]

My $. 02.....



Just installed the in tank pump kit on my 99 and have 5psi at idle/cruise and 0 PSI at WOT. I had a choice to replace the module with or without the pump for about $10 difference when my strainers plugged up with what looked like algae. The In tank pump kit was cheaper than replacing the old style module . Im going to see if my old frame mounted pump can get me some more pressure and volume with the intank still installed.

 

[JKinney]

DC replaced my vp44 under the 5yr 100,000 and I paid no deductable.



I dont understand these pressure # from this new in the tank system. Or I should say I understand what out TDR members are telling us, I dont understand DC's logic for installing this pump with such low #s.

 

[hmartin]

$. 02 more cents...

I also had the in tank pump installed when the injection pump crapped out at 55,000. The thing that raises an eyebrow is when I first start the truck it takes about 45 seconds for the pressure to come up to 9psi from 0! Anyone one else experiencing this? Currently 8-9psi idling, 6-7psi at 70mph, and 4-5psi with my foot in it.

 

[JBrownlow]

Have exactly the same numbers in all categories. The other thing that I do not like is the fuel gauge is now incorrect. Will stay on FULL for about 300 miles and then come down rapidly. Still not too sure where EMPTY is on the gauge. I have a 70 gallon aux tank and have not run the system to the empty mark yet. Not very happy with the entire set-up due to the lift pump and VP-44 failures. Has left me stranded a couple times now. Getting too expensive for my fixed income.



Truck is a 1998. 5, 3500, auto, bone stock with only gauges added.

 

[jeepit]

My understanding about the low pressures on the intank pushers is DC and Cummins don't care what the pressure is. They go by volume of fuel measured post filter. I believe they want 48 ounces of fuel in 25 seconds. I am not happy with this either. Looking for suggestions on another pump to bring up pressure.

 

[nps]

My understanding about the low pressures on the intank pushers is DC and Cummins don't care what the pressure is. They go by volume of fuel measured post filter. I believe they want 48 ounces of fuel in 25 seconds. I am not happy with this either. Looking for suggestions on another pump to bring up pressure.

True - there is a TSB posting these numbers as the minimum standard. My LP tests right at 48oz, and delivers 10psi at idle and 6 psi at WOT. Don't know what volume the new module pumps. I believe that with the original LP design, any less than the min volume would result in lower psi at the VP44. I can't imagine the physics involved with the new LP module that would allow it to deliver less psi yet pumping more volume.



While Dodge and Cummins no longer measure psi, it has been widely discussed that Bosch wants to see a minimum of 7psi at the VP44 inlet or a diaphram between the low and high pressure sides of the VP is allowed to move excessively, causing the diaphram to rupture and leak. This is one of the three common failure modes, the other two being wear of the pump barrels and failure of the electronics. Rebuilders have addressed the electronics and pump chamber failures with new parts. To my knowledge the diaphram still requires inlet psi.



For another pump - why not the 8psi carter as a pusher pump located down by the tank. Don't know how it would work with the intank module, but you can get one from Summit for about $90.



By the way, what happens to the original LP with the intank kit? Is it removed and the fuel line extended to the filter housing?

 

[jeepit]

It is my undertstanding that original LP is removed and new lines installed!?! Could a new stock lift pump be installed in stock position or on frame rail that would maybe help boost pressures? Or the Carter as nps indicated??

 

[nps]

The stock pump is a carter - just has the special Cummins/DC plug on the wire harness. There are 2 carter models - a 16psi (stock equivalent) and a 8psi. I'd go with the 8 psi model if another pump is in the circuit. I'd put it on the frame rail just to get it closer to the fuel - they seem to work better pushing instead of pulling. Although with the intank module installed as a pusher the stock location would probably be OK (providing you kept the stock mounting bracket and lines intact).

 

[JKinney]

I went with a vulcan big line kit, and moved the OEM pump to the frame 14 idle 12 WOT

 

[jeepit]

VP44 was damaged due to low pressures. Had intank pump put in. No other choice or I would have had to pay for the VP44 myself. Truck seems to have more pep but pressures are low. 9 idle, 2 cruise, wot 0. :--)

 

[JKinney]

What would happen to the pressure on an intake dc pump if a big line kit was installed?