I don't understand how a pusher pump works if I put a pump by the fuel tank that will just run constant with the ignition on and leave the stocker in there what regulates the fuel pressure will my pressure be off the wall or can I put a pump on the frame let it run constant and my stock pump will keep it regulated?

will that work

 

Why not just tap into the stock wire harness? That way both pumps will turn on and off via the ECM....... That's howe I did mine.

 

your factory lift pump runs constantly when your engine is running. The whole idea behind a pusher pump is that instead of having the pump try and suck the fuel all the way from the tank to the engine it only has to suck it out of the tank and then push it to the engine which is alot less work for the pump.

Im not a reall big fan of the dual pump set up. but if you want to run them both off of your factory harness one thing to consider is that your ECM was only ment to produce enough electrical current for one pump so if your running 2 pumps it could over load your ECM . You might want to just use the factory harness to run a relay that draws the power from your battery to run the pumps. Some people even use a relay set up with just an aftermarket pump since for more flow alot of times they will also draw more electrical current.

with my stock fuel system and just a edge juice with att. set to 5x5 at idle i had 12-14 psi of fuel pres. and at WOT i had about 1-3 psi.

I installed a vulcan big line fuel kit that also relocates the pump to just infront of the tank and at idle i had about 13-15 psi and at WOT about 7-8 psi.

then i installed my mach 4.5 injectors and would see 6 psi at WOT

This morning i installed the vulcan draw straw. That is just a bigger fuel pick up that gos into the tank and now i have 1/2" line all the way from inside the tank to the injection pump. Now a idle i see 15-16 psi and at WOT 10 psi. Which most people on here would agree is enough to have my vp44 live a long and happy life .

Lots of people buy a higher flow lift pump. Personally i think the factory lift pump is fine for 500+ hp as long as you have the right mods to your fuel system. it also was a cheaper option than some of the fuel pumps i see some have installed. how long my lift pump will last is a hole nother story though. only time will tell.

Justin

 

What regulates the fuel pressure?

If I take the stock one out, And hook up just my holley inline pump, what regulates the pressure, do i just hook it up to the stock wiring harness?

 

with the factory pump nothing regulates fuel pres. all you can get out of it is about 15 psi max. with a holly im not sure if there is some kind of regulator built into it other wise you will need to get one if it pushes to much pres.

 

Just run the Holley Blue with no pressure regulator. Should see FP at about 14-16 psi at idle and at WOT I see about 8-9.

 

I looked under my truck this morning (99 SWB 2500), and noticed there is not much room where the sending unit goes into the tank for working around. If and when I decide to relocate/upgrade stock LP with aftermarket (vulcan for example for reloc, or baby FASS for repl.), will I have to lower fuel tank, or is there an easier option?

 

Unless you plan on installing a Draw Straw, you will only need to cut the fuel line in front of the tank and install the pusher there. You are correct though there is not a lot of room there. Some people have just raised the box to gain access. Lowering and especially raising the tank has a really high suck factor to it.

 

This pump can do 50psi max, it is a fuel injection pump and it will over pump what i need, it would pump till it wouldnt pump no more, can i put a return line back into the pump.

 

Okay, I decided to do the holley blue, it is in stock and and ready to pickup. How do i hook up the holly blue, does anyone have pictures or does it go in place of the stock one

 

as long as you dont have an in tank fuel pump you should not have to drop the tank. One thing to remember in a standard fuel injection setup i dont think there is ever any fuel returning to the tank. its pretty much pumped up to a dead end, the injectors. on a cummins fuel is constantly being circulated. The way it was explained to me is there is a vane pump in the vp44 that bumps the PSI up to around 200 for the main part of the injection pump. all the fuel that goes back to your tank via the return line has all ready gone through that vane pump. it doent travel back to your tank at 200 psi because there is not enough of a restriction.

so your pump might not be able to hit 50psi because there is to much flow.

 

Okay, I decided to do the holley blue, it is in stock and and ready to pickup. How do i hook up the holly blue, does anyone have pictures or does it go in place of the stock one

I am going to the store tomorrow it would be nice if sombody had some details before the end of the night, please