I say go with the scotty max flow kit. I recently installed that on a buddy's truck and his WOT pressure went from 5 to 10 psi. The kit is 100% complete and really is a work of art. When I get my next paycheck I'm gonna order his kit. Let's put it this way, his line is 1/2" and his fitting are like 7/16". There's absolutely no restriction what so ever in this kit.

 

Thanks everyone.
More posts on upgrading fuel lines vs the pump is bad. Why is my first question. On a stock truck for now shouldn't the stock Carter be just fine? I plan on a comp come tax money time so the extra fuel will be nice if I upgrade the fuel lines. Last question will upgrading the fuel lines in any way void my warranty. I bought the truck used at a dealer and have a 2 year extended warranty plus I read the normal Cummins 100,000 mile.

Thanks again. This website is great.

Bill.

 

Install the walbro pump with a bybass regulator and forget about it unless you have money burning your pocket.

What's so hard to understand?

It will be much cheaper and easier than using two pumps and installing all new larger lines and changing restrictive fittings. If their so restrictive then why worry about overpressurizing the vp?

 

No one was talking TWO pumps here?? Just bigger lines and fittings.

Also, I think the topic was more relating to VOLUME, squeeze the same amount of fuel through a 3/16" orfice and see how long it takes to loose pressure on the other side v.s my 3/8 to 1/2" fittings. I personally think the oversized banjos are a waste of time, you can only oversize those things so far?!

That might be "what's so hard for everyone to understand"

 

My opinion? YES.

Most users report less fluctuation of pressure from cruise to WOT. (see BB's post, for real life results)

Probably. But, breathing on your truck wrong could probably void it to at the right dealer. I would suggest waiting till your out of warranty for ANY mods.

I seriously didn't touch my truck (besides regular maintenance) until I was on my own, no sense in fighting with them over what they will and won't cover because you tried to improve your vehicle!

 

Thanks P.J. I'm not even thinking about a Walbro pump and could care less about how it's better, it isn't a bolt on quick change for us normal weekend mechanics, I just want this truck to run and not kill the VP and the fuel pressure is somewhat low from everything I've read until the invention of all the Walbro threads and volume testing Yes I know DC has never claimed any pressure is necessary to the VP it's all volume or flow but for years everyone was living with pressure and now were on volume so throw away the gauge. I bought my truck 10 months ago and had a gauge I installed 3 months later due to this site, Thanks, really I mean thank you to everyone for telling me to put one in. FP went rock bottom so I replaced the LP now FP is still low at WOT, who or what do I believe, my gauge or DC/Walbro and you need a volume test

 

You are fine. Most pumps won't do as well right out of the box. If you want to help it a little for not much money buy some drilled out banjo fittings from Geno's. In the meantime just keep your eye on the guages.

 

Your pressure is low for a stock truck. I still get 12psi WOT on my 17 month old Carter 4601HP w/Comp off.
You can check your fuel filter, mine had a bunch of dark pieces of trash in the bottom of the filter housing. You might also check the quick connect fitting on the fuel line between the fuel tank and your FP-right before the FP, it's been reported that they can draw air into the system if they leak. Some folks cut that connection out and replace with rubber fuel line and small hose clamps for a perfect seal.