Engine/Transmission (1998.5 - 2002) Carter relocation questions

[Ncostello]

The most recent versions of the Carter made OEM transfer pump had the water proof Deutsch plugs and the terminals are protected by the black plastic cover. That was one of the revisions... and hence the need for the pigtail adapter sold by Cummins. My original just had the red and black wire and the connections at the motor body were exposed to the elements... a common failure point from corrosion.



Practical Solutions Diesel made me a "super" pigtail adapter so I could simply move my pump back by the tank. They used new factory plugs and 14 GA wire. Super job I might add.



Interesting point on the LP bracket. I was in the same boat as you Gary and didn't bother taking it off. Now I'm gonna have to take a look behind it. I'd rather not have it just sitting there if it serves no purpose. Hope mine dont block oil.

 

[Gary - K7GLD]

Let us know what you find behind the plate Neil...

 

[RobertMiller1]

Carter

I believe the Carter P4600H is the SAME fuel pump Chrysler and Cummins use in the factory lift pump. And it is a 7psi regulated pump.



the fact that 15psi is present on guages is probably due to the draw of the VP44.



the VP44 does not 'require' a lift pump in many applications. Chrysler 'engineers" decided they needed one. Made a bad choice, and then put it in the wrong location.



Makes as much sense as the work they put into their automatic transmissions.



Instead of reducing stall speeds and beefing up locking clutches in the converter, increaseing pressure to locking clutches, enabling lubrication flow in Park instead of just neutral. They add 6 helical gears to the planetary mass instead of 5... . go figure. I mean that is nice, but ever hear of someone losing a planetary gear assy in a 47re?



quicker firmer shifts, improved lubrication better torque convertor, line pressures AND A DRAIN PLUG would have been much better.

 

[Gary - K7GLD]

Sorry = wrong on the PSI of the stock pump - I have tested 2 of them OFF the engine, and they deliver their full 15+ PSI against a restriction as measured with a mechanical guage...

 

[RobertMiller1]

sorry...

getting too carried away in the rant... .



Gary, have you posted a how to on that bypass valve you made? sounds like a real good idea.



robt

 

[CFast]

so how many wires go to the stock LP? Are the threads in the fuel filter housing metric, or is it just the VP44? Anybody ever put a fuel filter BETWEEN the relocated fuel pump and the fuel tank? Man i really need to tear into my truck to look at all this stuff.

 

[Sticks]

Originally posted by CFast

so how many wires go to the stock LP? Are the threads in the fuel filter housing metric, or is it just the VP44? Anybody ever put a fuel filter BETWEEN the relocated fuel pump and the fuel tank? Man i really need to tear into my truck to look at all this stuff.

The LP has the same threads as the VP44, 12x1. 50mm

 

[RobertMiller1]

banjo bolts

I have bought the enlarged banjo bolts from Genos, but if I relocate the pump to the rear, it might be a good time to go to a different type of direct connector.



anyone have vendor and part number(s).

 

[Gary - K7GLD]

"Gary, have you posted a how to on that bypass valve you made? sounds like a real good idea"





ASK, and ye shall receive:



#ad




The above shows an exploded view of my home-made pusher bypass valve - all common hardware fittings, some slightly modified to suit my application, but easily accomplished with common tools.



#ad




Above is a blowup of the valve part of the bypass.



Below is how the valve parts go togerther:



#ad




And the finised, assembled setup:



#ad




The way all the above works, is that in NORMAL operation, the small drilled screw shown "floats", and when under mormal pressure and direction of flow, seats fully against the flat internal shoulder of the fitting seen - IF the pusher fails or stops for any reason, there is then SUCTION applied, pulling that same screw against the opposite side where the fitting has had a number of notches cut into it, this permits considerable fuel to flow around the "valve" - and tests show that I only lose 1-2 PSI at the VP-44 if I shut the pusher pump down completely - yet, if the stock LP quits, (as it did on our last RV trip!) I still show nearly 10 PSI fuel pressure at idle to the VP-44, dropping to about 5 PSI at heaviest towing load in the mountains - enough to get me safely home!



One added goal of the valve was to slightly reduce overall system PSI, since I was seeing PSI near 26 PSI before making the valve - PSI is now around 22, due to the 1/8 inch bleed hole provided in the floating screw part of the valve that provides a fuel bleeder in normal operation. An added benefit, is the the pusher is now quieter, since load is decreased - another nice feature, is that the whole thing is totally automatic, and operates completely without operator engagement.