Originally posted by KLockliear
Rod, what kind of power is your truck making now?
I'm still running tests with the Edge EZ in the 80 pony mode. We're not having much joy with the stocker fuel system. I've been able to drive my truck into vacuum, with only the EZ. I actually posted the following on the Diesel Truck Resource and didn't get to it here, so I'll paste it in:
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After running my 03's injection pump dry again, I decided it was time to get busy and look into fixing up this lousy fuel system. With only an Edge EZ in 80 HP mode, I've been repeatedly running my CP3 dry after long, hard, full throttle runs.
When new, our 03 would register about 9. 5 PSI of idle pressure, and at WOT throttle would pull down to approximately 5 PSI of pressure. Not wonderful, but also enough flow to keep the stock HO engine happy. Eventually, pressure dropped to 8. 5 PSI at idle, and 4 PSI at WOT. With the addition of the Edge EZ, my idle pressures haven't been changing much, however WOT throttle pressures have slowly been getting worse and worse, and recently I've been driving the system into vacuum, with stumbling after hard, full throttle runs.
This afternoon, we set to work and added our custom 12mm x 1. 5 x -8AN custom fittings to the CP3 and the bottom of the filter housing. Originally, we had planned to test out a -6 fitting kit put together by DTR's very own Ed "Looney as an Outhouse Rat" Looney (many thanks for the kit, Ed), however Cummins' new filter housing has a couple braces on it, and Ed's fittings with their larger wrench heads wouldn't fit for us. So we went with the -8 fittings from the 2nd Gen kits. In between these two fittings, we ran -8 stainless braided hose with some steel 90 degree swivels.
Installation was more of a headache than on an 02 and under. I learned some new swear words, until we noticed that you can see the bottom of the filter canister from the wheel well. After that, installation went MUCH easier
Anyway, end result: 10 PSI at idle, WOT throttle pressure between 2 PSI and 4 PSI. No stumble at all. We won't be running this system in its current incarnation for long, as we're stepping up to more ponies shortly, and moving to the PE4100 pump, however it does look as though the stocker lift pump can handle an Edge EZ with the addition of the -8 lines (we did try high flow banjos earlier, with no good results).
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I do need to add that my confidence in just the -8AN lines, with the EZ, is not exactly rock solid. I don't have anywhere near enough test miles to jump and down and say we solved the problem. Confidence in the PE4100 pump is high though, as its working extremely well under demanding circumstances on the 02 and under trucks.
I think the variability we're seeing is largely based on fuel quality. Canuck diesel is terrible junk, and we have more than our fair share of lift pump issues (stocker lifts/fuel systems on stock trucks can expect 30K out of a lift pump, until high flow bolts are added. Expectancy then goes up considerably (80K - 100K).
But I don't know if we're seeing the same bypass valve problem with the 03 lifts as we did with the 02 lifts. My truck is definitely not behaving as though it has a bypass valve problem, as the idle pressures just aren't dropping all that much. I heavily suspect that the new lift pump is just not capable in the puller capacity, and a stronger lift, such as a PE4100 (which can pull fuel) will end up being the final solution.
Attention: TDR Forum Junkies 
I could wrong on this one, but I think the VP44 was a similar design, flow rates just didn't really seem to enter into the equation during discussions. 
