Engine/Transmission (1998.5 - 2002) pumps, lines & whatnot

[JR2]

Just another bump to the top for the newbies. I wish some of the people on here would read the entire thing (well most of it at least). They would then find that PRESSURE is not what we want our systems to have, its all about FLOW. Somewhere in the middle of this long thread are the results of a test done with a flow meter on the return line from the VP, go find it and read all about it. Its the reason I don't have a high dollar fuel pump on my truck, all I did was move the stock pump to the frame with new lines.



Anyway end of rant and remember you can have pressure without flow.





JR2

 

[darkhorse]

NOT to start anything, or beat a dead horse - but I'd seriously suggest there may have been other issues with your "stock" setup that created your lower pressures - they seem to be well off of the numbers most other stock setups deliver under similar conditions, including my own in towing situations up Sierra grades for the short time it was still in stock condition... [/QUOTE]



I know it wasn't the fuel filter because I changed that several times. & when I put on the bigger lines I got a noticeable improvement in pressure without changing the filter. What other issues might there be?

 

[Gary - K7GLD]

"I know it wasn't the fuel filter because I changed that several times. & when I put on the bigger lines I got a noticeable improvement in pressure without changing the filter. What other issues might there be?"



Anything from a kinked/pinched or otherwise obstructed fuel line to a poorly sealed one sucking air - hard to say from a distance, but I *do* know the low "before" PSI you report is well off what most see in a properly operating system with all stock lines and fittings - shucks, with my all stock lines and fittings, and an added restrictive Frantz TP sub-micron filter in the line, I can shut down my added Carter pusher pump and STILL get better PSI than what you were getting...



Main thing is, you made a change that fixed your problem, whatever it might have been, and certainly, there's nothing BAD about bigger lines and fittings!



At some point, just for the sport of it, I want to at least swap over to larger banjo fittings to see what my PSI changes are - a guy was supposed to have sent me his after upgrading his system, but never did...

 

[darkhorse]

Anything from a kinked/pinched or otherwise obstructed fuel line to a poorly sealed one sucking air - hard to say from a distance, but I *do* know the low "before" PSI you report is well off what most see in a properly operating system with all stock lines and fittings -



The fuel lines I removed all seemed in good shape. No leaks or kinks evident. I had been advised my Lift pump was on it's last legs. The only thing I did was change the lines out of the lift pump through the FF & to the VP 44. The pressure has been up ever since. I do suspect the pressure relief valve in the LP isn't quite right as the pressure sometimes rises a few pound but then returns to the usual setting Once it went up & pegged the gauge.

 

[Gary - K7GLD]

Sounds like one of those "who knows" issues - perhaps a marginal pump into a line that kept it from reaching it's optimum operating rpm and volume - or a marginal bypass valve doing the same thing - the added improved lines and fittings, in your case, might have improved the ability to move more fuel further up into the pumps "sweet spot" of operation. .



"who knows... " :-laf :-laf

 

[rweis]

Well... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .....

and this might be a bucket we do not want to get into... ... ... ... ... ... .



What about a group of us (5 - 15) with DIFFERENT fuel supply setups, finding a really GOOD remote reading flowmeter ($1500?) and making a coordinated single purchase. Then each one of us install the flowmeter in their truck for a week or so and take readings. Then report back here say in April or so and we post what we found. The device would be available to anyone that bought in a share.



Something like:

OEM lp stock by tank, idle xxx, 1500 xxx, 2000rpm xxx, 2400rpm xxx

RASP, idle xxx, 1500 xxx, 2000rpm xxx, 2400rpm xxx

FASS, idle xxx, 1500 xxx, 2000rpm xxx, 2400rpm xxx

Stock, idle xxx, 1500 xxx, 2000rpm xxx, 2400rpm xxx

OEM lp with Carter 4601 by tank, idle xxx, 1500 xxx, 2000rpm xxx, 2400rpm xxx



All the xxx would be flow numbers and psi if you have that as well.



Bob Weis

 

[Sbonvo]

help

Sounds like one of those "who knows" issues - perhaps a marginal pump into a line that kept it from reaching it's optimum operating rpm and volume - or a marginal bypass valve doing the same thing - the added improved lines and fittings, in your case, might have improved the ability to move more fuel further up into the pumps "sweet spot" of operation. .



"who knows... " :-laf :-laf

I’m new at this and am technically deficient. I am frustrated. I have a 2002 3/4 diesel. I am on my fourth fuel injector and third lift pump at 86,000 miles. All service has been done at Dodge Dealerships. The system keeps failing and Dodge keeps replacing the pumps. I keep telling Dodge that there is obviously something causing the pumps to fail. Dodge says the computer tells them I have a bad pumps and that is what they replace. The warranty runs out in 14,000 miles. I need to get this resolved before the warranty runs out. I’ve parked the truck to avoid the warranty expiring. The truck is currently running following the last injector pump replacement. Any suggestion other than pursuing a Lemon Law case or spending more money by going outside of Dodge?

 

[steved]

I read this thread (wow!) and have this to say:



This thread proved that the VP-44 only needs 45 GPH (as was stated from cited literature)... at max burn you use approximately 15 GPH (was hand calculated) and return approximately 30 GPH to the tank (measured on several occaisions). So any higher supply and you are pumping more than needed (on a stock truck) it appears.



There are several variables on pressure readings... pressure will vary across the system depending on where you take the reading at... just look at the drop across a fuel filter for example. We can spout pressures all day long, but if they are not taken from the same place, they are not really telling us anything. By this I mean depending on where the pressure is read at, you could actually be pulling a vacuum at the VP-44 and still show a "positive" pressure on the gauge.



Also, most pump flow numbers are given at zero pressure... a pump that will flow 140GPH might only do 20GPH at 10psi... and there are several factors in this too... distance they are forced to lift the fuel vertically, distance they are forced to lift the horizontally, and line restrictions both before and after the pump. Just rememeber that because a pump is rated at XXGPH, that it will only do that with no head and no restrictions.



This is just something to think about... this thread was very informative...



Additionally, I'm running a FASS on my third gen and even though the pump can supply 90GPH, the CP3 is only fed what volume it needs at XXpsi as the FASS returns the rest to the tank... as stated in this thread, any pump that doesn't work hard will last longer which is true... the FASS only needs to overcome the internal bypass pressure (mine is now 13psi) and the pump freeflows the excess fuel (and heat) to the tank. So basically, you could get a spring for the FASS that is set at 2 to 3 PSI for the VP-44 and it "should" be very happy as it would have lots of volume and low pressure which I believe is the overall "goal" of this thread unless I missed something.





steved

 

[rubberneck]

I believe that industrial injection is now saying that this whole flow not pressure thing is BS. They have stated that anything under 9psi and we start to damage the metal seal in the back of the vp44.

 

[rweis]

I think there is a post (somewhere in the archives) that has the VP44 specs from Bosch that states 12-14 psi is the ideal input pressure. It might take a few hours (weeks) to find it.



Sticks works on VP44's at a south western rebuilder. Might be a good point of contact for the pressure / volume discussion.



Bob Weis

 

[rbattelle]

Lots of 3rd gen guys installing aftermarket pumps, lines, and whatnot lately. It's about time for this thread to come up again. Tons of great info.



Ryan

 

[PAbernathy]

I need to get this resolved before the warranty runs out. I’ve parked the truck to avoid the warranty expiring. The truck is currently running following the last injector pump replacement. Any suggestion other than pursuing a Lemon Law case or spending more money by going outside of Dodge?

Does anyone have any suggestions for his apparently continuing problem. Poor guy can't even enjoy driving his truck because he is anticipating/expecting failure.



I am at 92k miles on original/stock. Maybe I should take advice that I read somewhere and procure a lift pump for spare stock and carry it with me? I did see one post that someone offered their stock (currently working) pump when they upgraded: is that a possibility?



Thanks for all the great info as well as opinions. I feel that so many variables are at play that there is a chance that no one is wrong :-{}. I do believe that a stock lift pump is like motorcycling: there are two kinds of cyclists, those that have fallen, and those that will.



After 100K, I still won't have any money, but would like to "improve" my truck. Lift pump is probably (from what I've read) the 1st thing. Air filter, then gauges, then Edge EZ maybe. But no problems yet!

 

[csutton7]

my aeromotive pump is still pumping strong---chris

 

[Gary - K7GLD]

While this is a minor offshoot from purely "lines" and such, using the info presented in this and related threads has, I'm sure, helped me keep my OEM LP (relocated to frame) and added pusher all running perfectly for 48K miles so far.



Only fuel system issue to date was the VP-44, and THAT was related to a design issue and poor decision by Bosch to use a brass liner for the fuel advance cylinder - that early failure prone component alone has been replaced, and virtually ALL other mechanical and electronic parts were still in spec and totally serviceable and reinstalled into my pump...



I only discovered THAT issue upon insisting that ONLY the failed parts on my VP-44 be replaced by Industrial Injection Service.

 

[csutton7]

BTT---I was rereading some of this and on page 14 (I think) I stated where I changed out my pump after 2. 5 yrs, but this is wrong, as it went 3. 5 yrs (07/01 to 10/04) and yes it was a loose ground screw, that was the problem--it is now my back up pump--the newer pump has been in for 2. 5 yrs (10/04 to present)---gravity fed, relay wired and separate regulated return line is what I say is the keys to the system---thought I'd bring it back up since there a little discussion on the aeromotive pump... . have fun reading----chris

 

[Bob Wagner]

good to see you back chris.

 

[csutton7]

I'm never far away--I just don't post as much as in the good ol' days---chris

 

[CUMINNTSTRKN]

Wow Chris talk about bringing up the past.



Jim

 

[rweis]

csutton7 - a couple of questions



The gravity fed part, I am about to do the "draw straw" and reread this entire thread just to rethink the "draw straw" and read where you gravity fed yours.



Where did you put the feed in the tank? in the bottom?, in the side?, in the side with a 90* to the bottom? what bulkhead fitting did you use? how did you seal it to insure it would not leak with tank flexing? how did you protect it from road damage? at what point do you refuel?, 1/2 tank, 1/4 tank? etc etc etc. Any and ALL info / pics you could share would be helpful.



Just trying to get the best fuel feed.



Your Aeromotive seems to be one of the solutions for electric pumps.



Bob Weis

 

[csutton7]

Jim--yea no kiddin---good to hear from you --hope all is going well...



Bob--out the bottom with a -10AN 90* bulkhead that I cut down(long side cut) and chamfered the inside and I put a screen in it(came with another pump or maybe it came with the aeromotive--I don't recall now)--not sure it's still there, but it seemed prudent at the time---I got two poly washers(one inside on outside) and I had to make a metal washer for the outside of sheetmetal, cuz I did'n't have one the right size(small shoulder on bulkhead fitting)---this is because that shoulder is too small and would pull through the tank upon tightening the nut---I then installed a shutoff, to make pump changes, filter changes a breeze)---an inline Aeromotive filter and then the pump---all plumbed in -10AN stainless braided(doesn't need to be, but I was thinking it needed to look good)----after the pump it's -08AN stainless up to a Racor filter--out of the filter into an Aeromotive regulator then to the VP and the return line comes back and ties into the overflow tube of the filler neck--I used a 3/4" tee to tie it in---I can see the fuel being pumped back into the tank at anytime a great way to make sure the pump is running---as for road rash I've yet to encounter an issue, but I'm lifted 7" now and was

4. 5" when I did this----I always intended to do some sort of protective plate, but just can seem to figure it out, although I do think I could make up a stainless or aluminum plate that would attach to the tank straps----but there's another thread going where a guy is looking to see if this company still is making or has a sump that's much easier to install--hopefully this link will work---- https://www.turbodieselregister.com/forums/showthread.php?t=178677&goto=newpost ---my pump is run off a 30 amp relay triggered by the oem lift pump wiring also--pump is mounted on the frame right in front of the tank----hope this helps---I'll see if I don't have some pics --if so I can email them to you---what's your email address-------chris