I am running a airtex lift pump and have my pressure gauge hooked up at banjo bolt coming off the injector pump. I was looking and Vulcan they sell a big line kit with a tee that I can mount the pressure solenoid. Just doing a 1/2 inch line from the fuel filter housing to the injector pump- would that be beneficial at all since the rest of my lines are all still factory. What are yalls opinion on this.

Edited February 15, 20178 yr by 2001cummins
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I think anything is a benefit, especially replacing the restrictive banjo bolts.  But the main feed line coming from the tank is still a big restriction.  Running the big line kit from the filter to the VP44 will not be an ultimate fix to FP fluxuation problems. 

The OEM supply fuel line size is (I think I remember) 5/16" ID.  Thats not optimal but its sufficient as long as HP isnt crazy.

 

The real problem is the banjo bolts as they restrict overall flow due to their design.  So point I'm making is, if the Big Line kit eliminates all banjo bolts, even the one at the inlet of the fuel pump, then the OEM fuel line size from the tank to the fuel pump wont be as much as a hindrance as you'd think.  Actually you'd be surprised at how much less the fuel pressure will drop throughout the throttle too.

I have looked at similar kits. And I will be ordering one in the future. I currently have a GDP fuel boss pump. I will be replacing the line between the fuel filter and the vp44 and the line going from the tank to the fuel boss. the rest of the lines have been replaced.

 

Lose that restrictive line from the fuel filter housing to the injection pump and let your fuel system flow at it's full potential! The GDP Big Line Kit is an excellent addition to our GFS Performance fuel systems. Gain 2-3 psi right where you need it, at the injection pump inlet!

The factory hard line from the fuel filter to the injection pump is less than 1/4" in diameter.

1 hour ago, Jolsen said:

The factory hard line from the fuel filter to the injection pump is less than 1/4" in diameter.

 

Strangely that can be hit and miss.  I've seen them 5/16" ID and I've also seen them (on my truck) where one of those two lines was only 1/8" ID.  I researched this some years ago and people had varying results with what they had too.

A big line kit is on my list as well.  Tank to vp44

 

L8tr

D

I still have my factory lines from the filter to the vp and they are maybe 1/4" but the banjo's are horribly small. The bolts cant be much over 1/8" of an opening. Very restrictive.

I need to add that I have these lines and bolts in a bin on my shop wall and not on the truck. Sorry about that.

^^^^^