fuel pressure question

[Archive]

A question prompted by the thread in the Product/Assessories forum concerning fuel delivery and Prim-Loc.
My Dodge serviec manual says that the lift pump supplies 3-5 psi to the injector pump.
The maximum drop across the fuel filter can be 3 psi.
However, in the aforemention thread, John states that 12v supply should be in the vicinity of 28 psi.
And Dave Fritz's info on the 1992 Ram Diesel Engine Specs says that the fuel pressure should be 18-24 at idle, 28-36 with no load which is in the same ballpark as John's.
Would someone help me understand how to get from the 3-5 psi in the service manual to the higher pressures noted elsewhere?
thanks..... gary

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'92 W250 LE 4x4, NV4500 5spd, Borgeson steering shaft, PrimeLoc

 

[Archive]

It may have something to do with the P7100 pump needing higher supply pressures than our VE's.
Does the book specify between the 144 pump and the 205? Other than that, dunno #ad


J-eh

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Jason Hoffman
Lil' Mack - 89 D250LE 5 Spd 3. 54 Reg Cab. K&N,"tweaked pump", BD Injectors, Banks Pyro/Boost, 3. 5" Exst tail section straight. E&M Custom seats. Bosch H4, PIAA 80W/80W HdLites. 100W Drv,55W Fogs. 232,500 miles (372,000 Kms) 7700 Hrs. Cummins Power Booster member.
The Original Turbo Diesel

Lil' Mack Pics

[This message has been edited by Lil' Dog (edited 11-20-2000). ]

 

[Archive]

My service manual(which I bought new with the truck in '92) refers only to the VE pump without specifing numbers.
John's references to 12v pressures may be refering to the p7100. However, Dave Fritz's specs are directed to our VE pumps.
Still a mystery to me... .
gary

 

[Archive]

I'm in the process of adding two fuel pressure guages(before and after filter). Will let every one know what the numbers are.
Gene
92 350 4x4