Fuel Sump??

[TROJAN366]

This is a throwback lol. Since posting this I did swap to a PPE pickup. With no other changes the truck makes 2psi more at idle. Based on that I would assume that there was a restriction in the stock sump. I'm not sure it made any difference on horsepower but the pump is able to maintain more supply pressure at wide open throttle and I can't imagine that hurts anything.

 

[Harbin_22]

This is a throwback lol. Since posting this I did swap to a PPE pickup. With no other changes the truck makes 2psi more at idle. Based on that I would assume that there was a restriction in the stock sump. I'm not sure it made any difference on horsepower but the pump is able to maintain more supply pressure at wide open throttle and I can't imagine that hurts anything.

Mine gainded at least 1 psi at idle after I put the sump on. Not going to pick up any power since my RP was perfect before.

 

[c20elephant]

Stock LBZ sump pickup.
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http://www.duramaxdiesels.com/forum/showpost.php?p=924412&postcount=2007
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http://www.duramaxdiesels.com/forum/showpost.php?p=924371&postcount=2005
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[Chevy1925]

Well, I'm wondering if it's "stock" vs "stock-modified".

A stock fuel pickup was found to do a great job at draining the tank to low levels but at the same time was also found to be a restriction during high fuel demands (don't know if there is an exact HP limit), so many people modified their stock pickups to allow more flow, but in doing so may have created issues when the tank gets low.

After seeing it done in pictures and then actually doing it myself, I can see there being a HIGH level of variability from one person's mod to another that could cause some to have issues while others do not. Having to manually cut a hose to length and try to route it properly in the bucket introduces a chance for many variables. That said I mocked mine up several times and measured several times before cutting and routing, and I've run mine very low and not had an issue during daily driving (racing may be a different story but I've never tested that).

It was like the Eaton E-Lockers where several of us had Zero issues with wires rubbing, while others had failures due to wires rubbing on the ring gear bolts. The instructions allowed for variables which caught some and not others (whether by being careful or shear luck).

as long as lift pump pressure stays positive and you dont drop rail pressure due to lack of fuel, the pick up shouldnt matter.

i went from a stock pick up to a PPE long ago thinking that would solve my low rail pressure issue (this was on a stock motor just before i went twins). there is was no difference in rail pressure or lift pump pressure. Im wondering though if the 5/8" PPE pick up is whats keeping my ad2 lift pump alive though. it was installed in 2009 and no issues since.

Like you, i have no problems with 1/4 issue and i continually run it down to 3-4 gal from empty without issue. ive been as low as 1/2 gal from empty and still drove just fine. it wasnt all that hard to figure out the hose length. take a bit of time to measure it out and drop it all in.

the guys i see having 1/4 issues are the ones using a different draw straw outside the stock sump. without baffling around, its going to cause an issue unless you get that pick a nuts hair off the bottom of the tank and can keep fuel around it.