5.9L 24V Performance Discussion of 24 Valve 5.9 Liter Dodge Cummins Diesels with VP44 Injection Pumps Related To Performance And Longevity

Fuel Pressure Problem

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Old Jun 16, 2007 | 10:38 AM
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Default Fuel Pressure Problem

I just installed a Glacier GFS-392 Performance System. Installation went without a hitch and once the truck started it ran great. Problem is startup, it doesn't want to start. Emailed Richard a Glacier and he sent a writeup describing how to repair.

The problem is that the VP ran with low fuel pressure between 4-11 psi which damaged the diaphragm that seperates the high and low fuel pressure at the VP.

The solution requires disconnecting the ground from the ECM and the ground to the battery from the wires and connecting it to a switch that does not recieve power during cranking.

Has anybody done this? Where did you connect the wire? Which wire is it (ECM)? Should I just reinstall the old lift pump until the VP goes out? Any advice would be helpful.

I know I need to replace the VP but would like to prolong this as long as possible or at least until I figure out which VP to install.

 
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Old Jun 16, 2007 | 11:00 AM
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First I ever heard of this one. I would be interestd in seeing the writeup though if you could either post it or send it to me.
 
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Old Jun 16, 2007 | 11:03 AM
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When you bump the starter does the pump run. This is what's supposed to prime the system. I assume your using the factory trigger to run the pump. Also what fuel pressure are you running at right now.
 
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Old Jun 16, 2007 | 11:59 AM
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With the new pump around 17+. If the truck sits for a while it starts right up. If I run it and after a couple starts a no start happens. When I removed the relay during the no start, it started up easily (then quickly shut the engine off).
Prime system works, I have a gauge and it shoes pressure.

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Be back in an hour
Honey dues just caught up with me
 

Last edited by Greg; Jun 16, 2007 at 11:59 AM. Reason: Automerged Doublepost
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Old Jun 16, 2007 | 12:22 PM
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Sounds to me like your VP is goin. One of the primary symptoms is that it won't start when hot. If you shut the truck off, the VP44 has to cool off before it will re-start. If this is the case there's not much to do about that except replace it, unless Richard has come up with something new.

Not that I'm reccomending for you to do it, but mine started doing that a few years back. At the time I couldn't afford the new pump so I milked it for a few months by carrying a cooler full of gallon jugs of water around with me. If I needed to start the truck back up before it had a chance to cool down I would drown the pump with cold water and it would start right up. ONLY DO THIS IF YOU KNOW YOUR PUMP IS BAD AND YOUR WAITING TO REPLACE IT.
 
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Old Jun 16, 2007 | 03:09 PM
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11psi is low pressure????? First Ive heard that
 
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Old Jun 16, 2007 | 03:27 PM
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Even on the 4 psi end, it's a problem but not what I would consider a big one if it's only there for the few seconds at a time when your workin it. Dodge says it can drop to 0 for those short periods of WOT without hurtin it. Not that I'm aggreeing with them, just illustrating the point. That's also why I'm curious to see this write up, this sounds like a whole new concept to prolonging the life of a dying pump if it works.
 
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Old Jun 16, 2007 | 03:33 PM
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I'm curious how shutting the ECM off during cranking will help a "no hot start" pump. Pump cool fuel thru it? Or get the diaghram back the way it needs to be? Keep us informed on what works and doesn't.
 
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Old Jun 16, 2007 | 06:03 PM
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The problem is there is a diaphram that reacts to high/low pressure from the lif pump (hope I am explaining correctly). If the VP sees higher pressure from the lift pump during startup the truck doesn't start. When I removed the relay, shutting the lift pump off, the truck starts properly.
And
If I let truck sit for a while it starts up.

Once I get home I will post the write up.

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Also
Old lift pump was all over the place. At idle it would drop down to 0, 4, 6 psi etc. Once going pressures would go up to 9 through 11.

I am using a Quadzilla Recon (digital) to read pressure.
 

Last edited by Greg; Jun 16, 2007 at 06:03 PM. Reason: Automerged Doublepost
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Old Jun 16, 2007 | 07:15 PM
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That higher pressure your reffering to is the same problem that FASS users had to address when it was new to the market. But they were dealing with 22psi plus pressures that were causing the hard starts.
 
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