what was done to correct the problem? when I turn my key on the pressure will go up to 18-19 psi.

 

I don't know if this helps or not, but here is the way I understand my set-up. I have a walbro set-up (similar to yours from wide open diesel). Mine came with a trigger wire to run from the power wire at the stock lift pump (which is controlled by the ecm) back to the new walbro pump. This trigger wire would send power to the lift pump when you turn the key on to prime the system and then turn the pump off till the truck starts, then powers the pump again.

Did your kit come with a trigger wire to run from the stock lift pump wire?

Scott

 

It has a relay that connects to the stock lift pump wiring harness.

 

That's the way it should be.

 

Let me know if this makes sense

I see two choices
1 I could reintall my old lift pump and deal with fluctuating pressure,

2 install a valve to turn down the pressure to 5-7 psi. I have read on bluechip.com that at this pressure the inj pump would not suffer performance losses. This is a temp bandaid until the inj pump is replaced. Its just hard to replace it when I see 21+mpg on the hwy with great power.

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question is

what type of valve?
ball valve

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i'll answer my own question
needle valve

 

I won't argue with anything that Chip put's out, he is one of the most knowledgable out there on these pumps. But I don't like it that low. I think it will run just fine off those pressures, I just like a little more cooling factor then that. If your having troulbles with hot start's it's not gonna matter much longer anyway. That's a pretty advanced stage of the pump dying and it's gonna go quick from there.

A commonly overlooked problem on these pumps is the overflow regulator. It's a banjo bolt on the return line of the VP that is spring loaded. It's designed to hold the internal pressure of the pump at 14psi. If this spring gets weak it opens up with to little pressure and let's the fuel return right back to the tank, not getting an adequate supply to the injectors. If it sticks shut it holds to high of pressure and put's the VP into a limp mode so to speak. This is a $14 part from the dealer that you are gonna need to change when you replace the VP anyway. It's always worth a shot. Takes 10 minutes to change and it's cheap.

 

Scan through this article, it will give you some highlights of your fueling system. https://www.dieselbombers.com/98-5-02-cummins-24v-5-9l-vp-44-tech-talk/2670-guide-24v-fuel-system.html

 

Great advice will consider a $14 banjo bolt cheap and worth the try. Unfortunatly I will not be able to check it out until next week due to work.
Once I return I will replace the banjo and give an update.

Regarding Richard's write-up, I emailed and ask if I could post it, the write-up is his.

To all that answered
Thanks, its is good to have others with the same interest.

 

Galcier's write up
Thanks Richard

Spread the knowledge

Usually hard starts are only encountered on the 1998.5 – 2002 Dodge Cummins with the VP44 injection pump. If this occurs it is usually on a VP44 with high mileage, and/or a VP44 that has been subjected to around 5psi of fuel pressure or less. It is more likely to occur when the weather is warmer/hot.

Explanation of Diaphragm: The diaphragm in the VP44 is designed to move about .5mm with proper fuel pressure (about 7psi min.). When the VP44 is subject to about 5psi or less the diaphragm can move up to 2mm, an increase in movement of 4 times more than what it was designed to move. With this type of movement the diaphragm will eventually develop stress cracks thru out the body of the diaphragm.

One job of this diaphragm is to separate low fuel pressure and high fuel pressure in the housing of the VP44, when the cracks are present this separation does not occur. This will lead to hard starts even with a stock OEM lift pump!! Here is a simple test:

Note: Not all failed pumps with broken diaphragms will start with low to no fuel supply. Sometimes the diaphragm is so broken that charging pressure is not able to build to a level that allows the pump to deliver fuel. Try starting the vehicle without waiting for the fuel pump to cycle. Meaning when you turn the key to the on position immediately engage starter.

Or:

Unplug the lift pump or remove the fuse so the lift pump does not operate.

Note: If the engine operates without fuel pressure for a period of time the VP44 will be destroyed. Understanding this condition, start the truck. If the truck starts shut it off immediately!!!! This test just indicated that the increased fuel
pressure from the new lift pump is overriding the thinner diaphragm and/or cracked O-rings surrounding the diaphragm in the VP44.

There are a few solutions to this:

1) Repair the VP44. VP44’s were manufactured with a thinner diaphragm which can and will cause hard starts with hot weather and or higher fuel pressures. Thicker diaphragm’s for the VP44 were released around 2003 for correcting this situation. Remember it doesn’t matter if the VP44 has the thinner or thicker diaphragm, if the VP44 has been subjected to a failing transfer pump (lower fuel pressure) or a failed transfer pump it will lead to this problem. The damage was done by the failing or failed lift pump before the new pump was installed.

2) Lower the fuel pressure from the new system.

3) Most customers prefer the higher fuel pressure. If this is the case we recommend an oil pressure switch (Honeywell Hobbs part# 78143) on the ground side. This is done by placing the oil pressure switch in the oil gallery (on top of the oil filter). Then disconnect the ground from the ECM and (if it has it) the ground to the battery from the wires. The ground wire is then connected to the oil pressure switch. This will delay the lift pump until the engine has 3 – 4 pounds of oil pressure.

4) Move the relay power wire from the battery positive to a circuit that isn’t hot during cranking. This will give zero fuel pressure during cranking and allow the pump to come on as soon as the key is released. Good results have been had by using a fuse tap and connecting to the power window circuit in the fuse box itself.

 

If I'm reading this right it sounds like a lot of work to go through for a temporary fix. If this diaghram is bad your pump is gonna fail. By deleting the trigger relay from the ECM you are just buying yourself a little time for it to fail at an even more inopportune time in the near future. Not to mention the extra time and expense of the pressure switch and other misc items needed.

I may be way off base in my understanding here though.