Bart Timothy

I believe the VP44, also, was designed to suck its own fuel. They are used in several apps over in Europe without a lift pump. The biggest difference between those apps and the 5.9 Cummins is they are all smaller displacement V6's, in smaller vehicles. So this might be why Cummins decided to use a lift pump -- to make sure there is a sufficient fuel supply. This is simular to Cummins' use of a lift pump for supplying the CP3. FWIW, I have a friend who has run without a lift pump on his '04, just like the CP3s on Chevs, and it ran fine until he turned up his Edge to around level 3. Why do the Chevs run without a lift pump and the Dodge needs one? Is there a plumbing problem between the tank and injection pump which the 2nd and 3rd gens share?

The first time I ever saw a VP44 torn apart was 5 years ago, and the first impression I had was it really only needed just a couple of psi of fuel pressure to operate properly (yes, these lift pump and fuel pressure arguments have been going on for over 5 years now). In fact, it looked as if excessive fuel pressure would actuallly do them harm, especially in the area where the vane pump is located. The extra pressure looks like it can put additional, unwanted, thrust on one side of the vane pump, which looks to be not designed for any kind of thrust.

As stated previously, the ECM cuts back lift pump pressure, during cranking, to improve a hot hard start condition, which not all VP44s seem to have.

What really looks like a killer, though, is fuel pressure fluctuations, which appear to eventually kill a couple of inside seals on the 100 psi side of the pump. These seals are pretty tuff, but it's not hard to envision how they could crack out, given intake pressure fluctuations amplified by the vane pump. When these seals go, it causes the 0215 code that everyone fears. They, along with fried electronics, are probably the 2 biggest VP44 failure points. From what I understand, mechanical failure due to improper lubrication from lack of fuel doesn't appear to be all that prevalent any more, since Bosch improved the machining and metalurgy of the VP44. When I see people having to use a needle valve snubber to keep their fuel pressure guage from bouncing, I see an eventual VP44 failure. Also, what's irronic is, those pressure fluctuations are also what's killing lift pumps, and the lift pump, itself, with its internal pressure regulator, and the pumps location, could be the cause of them.

I hope you guys get the hydralics, and this fuel pressure regulation thing, worked out because it may well be the answer to many lift pump and VP44 problems. These Walbo threads have been entertaining and educational, and the Walbro is an excellant pump. If the word "FORD" haddn't been mentioned in any of the posts, reception of the Walbro would have probably been much better. In the mean time, a simple stock lift pump relocation off the engine, back to the frame by the fuel tank, goes along way toward making lift pumps and VP44s live longer.

That's my 2 cents worth.

Bart

P.J

Ah Ha!!
A vote for relocating the LP!

Time will tell on any and/or all of these thoughts and ideas, I am truely suprised and impressed at the strides made here with the threads started and maintained by SuperDuty.
Apologies to all for any.... less than productive post(s) I may have made on the subject over the past month.

043500QC

I fully agree P.J. I think for a "fairly stock" application, the relocation kit is a vast improvment. But in mine/my dad`s case, he`s far from stock, thus the feeling of needing more flow/psi.

This thread has been very civil when compared to the other Walbro threads, and for that, I thank everyone. I have no interest in getting caught up in a debate here. My main goal is to get this system working, not only so my dad has the fuel pressure his truck needs, but also to serve as a guide to anyone else who may want to try this. Like I stated earlier, I will be using this same pump on my truck as well, so that should speak to my confidence in this pump( if that means anything to anyone else, lol).

I`m of the proactive nature, I`d rather do everything I can to prevent a common problem before it happens to me. My truck might not quite need the Walbro yet, but I sure don`t think I`ll be hurting myself by going on and installing it.

Bart Timothy

Believe it or not, this fix has been around for at least 5 years... ever since Bill Kondolay, from DTT, paid good money and hired a hydralic engineer to find an answer to lift pump failures. Bill's old 2000 CTD was the first time I'd ever personally saw the relocation, at May Madness 2001, and this fix has been working fine for 5 and 600 hp trucks since then. The difference between now and then was VP44 failures didn't used to be as common as they are now, which I think is attributable to the trucks being newer, with fewer miles and hours on them, back then.

Superduty

Lets not start a debate about whether pumps push or pull or anything like that in this thread. Please start this discussion in another thread.

This thread is reserved for getting the Walbro working on the trucks in this thread.

This comment was made about some posts that have since disappeared.

upersleder

has anyone increased the size of the return line yet? that would have been the first thing i would do.

Geico266

I agree, but IMHO, you'll need to modify (cut off) the ends of the fuel tank module lines. The return & supply lines at the fuel module are "necked down to .200 & .275 (respectively) to accomidate the factory quick disconnectors. The same can be seen when you disconnect the supply line going to the stock LP. These will be restrictive to a high flow pump.

The good news is there is an "unused" 1/4" port that could be used as a second return line.


Also, there appears to be a "oneway valve" on the supply line at the pick up point. When I blew through it (on the supply side) it was very restrictive. I could not blow through it from the reverse side.

Sea01Cummer

Have you guys tried the bigger Swagelock yet? I am eagerly waiting to see if it works.

Stevo

043500QC

Nope, haven`t gotten it yet. The supplier he ordered it from had some computer issues and for whatever reason it didn`t get ordered till Wednesday(he called for one Monday). Its supposed to be here next week, we`re eager to get this going to man.


"has anyone increased the size of the return line yet? that would have been the first thing i would do."

We have upsized the return where it was plastic line only. If the larger Swagelock doesn`t work, upsizing the entire line is our next step.

Speaking of this, I know it would be hard to upsize the engine side of the return, but what do you think of using 1/2" line all the way back to the tank, then drilling the tank and threading a 1/2" nipple directly into the tank. That would make the return 1/2" all the way back except for the T that runs from the back of the head and the return on the VP ?

043500QC

But if you use one of the "big line" relocation kits (which we did, the Vulcan one), you allieviate that problem, or at least the supply line part of this problem, correct ?

Thats very interesting, may not be a bad idea there.



Hmmm, wonder if thats there to work in conjunction with the "check/relief valve" on the back side of the VP ????

Geico266

Better ask Mr. Wizard SD. I don't need the grief of defending my answer.

Sea01Cummer

We don't need that kinda crap, we are trying to figure this out not test ego's

Any new news on the bigger regulator?

Steve

043500QC

Aww, come on man. I`m not trying to start anything, I just wanted your opinion on it, thats all.

Superduty

Why don't we get the bigger regulator installed with stock lines and see what sort of pressure we have to start with. Once we have some data, then some decisions can be made.

You guys are running a Walbro. It will push the fuel if it needs to.

It would be helpful if someone put a bypass across the VP44 without a regulator (ie just a plain hose) and got us the pressure at the VP44 inlet. That would give us an indication of the backpressure in the return line. Once we have that number we can make some decisions. Worst case backpressure will be at idle, because that is when it is returning the most fuel. Just install the line, idle the engine and take some readings.

jthorpe

2 down and more to go if this kind of talk continues, gentlemen. We've given plenty of warnings. The warnings are overwith now. Let me say again, this will not turn into a ATS/DTT type war of a couple years ago. You guys are your own worst enemy in this. Keep it on the level, and the locks won't come out.