1st Generation Dodge Cummins 89-93 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with Rotary Injection Pumps

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  #11  
Old 12-07-2009, 11:13 AM
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Excessive case pressure being expelled after the throttle is lifted. With a VE you will get smoke, with a VP44 the truck often dies. The return side is too restricted, switched to an A1000 and bypass regulator, problem fixed.
 
  #12  
Old 12-07-2009, 12:48 PM
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It's my understanding the factory/OEM fuel return orifice is sized to work in conjunction with the case pressure regulator.

Are we talking about the resulting case pressure spike as the regulator backs off with side-stepping the throttle after a high RPM run?

Bobby, your incoming fuel pressure is regulated isn't it?
 
  #13  
Old 12-07-2009, 12:57 PM
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Originally Posted by BC847
It's my understanding the factory/OEM fuel return orifice is sized to work in conjunction with the case pressure regulator.
But, we are not talking about a factory or OEM quantity of fuel.

Originally Posted by BC847
Are we talking about the resulting case pressure spike as the regulator backs off with side-stepping the throttle after a high RPM run?
Yes. If you were to remove the KSB completely, use an open return fitting with the bypass regulator on the return side to control pressure, this would not be the case.
 
  #14  
Old 12-07-2009, 01:27 PM
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Got'cha.

(Folks still need to keep up with the throttle index though).
 
  #15  
Old 12-07-2009, 03:46 PM
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Originally Posted by Smokem
Excessive case pressure being expelled after the throttle is lifted. With a VE you will get smoke, with a VP44 the truck often dies. The return side is too restricted, switched to an A1000 and bypass regulator, problem fixed.
Originally Posted by BC847
It's my understanding the factory/OEM fuel return orifice is sized to work in conjunction with the case pressure regulator. Are we talking about the resulting case pressure spike as the regulator backs off with side-stepping the throttle after a high RPM run? Bobby, your incoming fuel pressure is regulated isn't it?
Read more: https://www.dieselbombers.com/newrep...#ixzz0Z2eDSPJF


Yep, I have a aftermarket pump with a bypass reguator, 15psi. Never watched the gauge when letting off to see if it jumps though.
 
  #16  
Old 12-07-2009, 04:13 PM
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Is that the spike that can kill the shut off solenoid?
 
  #17  
Old 12-07-2009, 04:50 PM
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I would think so Richie! Could be wrong though, I dont know the inside of these pumps like some of y'all.
 
  #18  
Old 12-07-2009, 06:07 PM
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I don't even know the outside , let alone the inside of these pumps.
 
  #19  
Old 12-07-2009, 06:11 PM
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I just keep playing with different parts and it has seemed to work somewhat good so far, I usually learn about it AFTER I mess it up and have to go back and fix what I did...
 
  #20  
Old 12-08-2009, 11:50 AM
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The only reason the vane pump is integrated into the VE or VP44 is for static timing alteration, lose the KSB and a lot of issues will follow suit.
 


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