Engine/Transmission (1998.5 - 2002) looking for input about new fuel system

[BRI7070]

Well I have gone thru 2 L/P and the 3rd on started acting weird. It will run for 5 minutes and quit. If I restart it the L/P will run for 5 min and quit again. I can do this all day but takes too long to get to work.



I have removed the L/P and installed a Carter 4601HP (14psi/100gph) back by the tank and going directly to the filter. Fuel pressure is 13PSI at idle and 4PSI at WOT. I would like more pressure all around.



Here is some questions.



What is causing all the failures I have read about?



Why are the Holley and Mallory pumps failing?



Is it possible to drill and tap the fuel filter from 12X1. 5 metric to 3/8" NPT? 1/2" NPT?



What is the PSI/GPH of the stock lift pump?





With the Holley Blue pump there is a spring loaded bypass valve to regulate the pressure. Stock is 14PSI but you can get a 19PSI spring and you can shim that for more pressure without sacrificing volume.



What determines the pressure of the carter pumps?

The 4600HP is 7PSI/100GPH and the 4601HP is 14PSI/100GPH and I cannot see a difference.



What are you using for a fuel system?



TIA

Brian

 

[Opz01]

Brain,



I went through my share of pumps as well. When I went with bigger injectors one pump just wouldn’t cut the mustard. What is working for me is the following set up. I run a AN6 fuel line from the tank to a prefilter, a $32 PermaCool filter assy on the outside of the frame back by the tank. (Replacement canisters are $12. ) Then I routed the fuel line over the rail to a 4600HP then to a 4601HP. (Both pumps are inside the rail. ) Then to the factory fuel filter housing. This set up did require using a relay to power both pumps. For what ever reason the 4600HP is less prone to failure when being used as a pusher with diesel. I am at 21. 8-23 pounds pressure at idle. Rarely have ever experienced hard



starting. And when it happened all I had to do was push on the accelorator. I don’t think this is the best answer, I have some ideas on a better system hopefully I will be running it in a month or so.

As for drilling and tapping the fuel filter houseing… I don’t see what you would gain from it especially when you can use an adapter. (AN6 to Webber)



Hope this helps and good luck,



Opie

 

[cscott]

The stock lift pumps fail because they are designed to push not pull and the stock location has them pulling a long way.



I guess you could re-tap the fuel filter for NPT but if you are asking because you wish to run the AN type fittings there is a fitting commonly referred to as a WEBER fitting that is metric to -06 AN. Product Engineering also makes a fitting that is metric to -08 AN.



The Mallory, Holley, and Carter pumps fail mostly because they are not designed to deal with diesel fuel, it rots the seals. Also many Mallory pumps are not designed for continuous use.



Rather than run 2 pumps you might want to look into the Product Engineering PE4200. It is designed to run continuously, works fine with diesel, and has a 2 year warranty. It is internally by-passed and factory set at about 18-20 PSI



If you have any questions please feel free to PM me.



Good luck



Craig