I purchased my 2003 Duramax brand new and since that time and about 2 times a year I tell myself that I should install a lift pump. I certainly believe there is value in doing so and it is about that time of year again for me to tell myself that I should install a lift pump. In all seriousness I do believe that installing one, especially one along with better filtration is a good thing to do. However, I have never had any issues for not having one and the oem size replacement fuel filters did improve with time.

 

I put the FASS no drop on my 17, when the factory lift pump died, I dealt with FASS when the first started two brothers, got in a fight now he owns Air Dog

 

Build your own. Filter heads, filters, plumbing, pump, controls, wiring, shut-off valves. It's not rocket science. And it's significantly cheaper than commercial products.

 

Curious why you're talking about the possibility of a new engine at those "miles" ??

As long as you take care of it and keep the fuel system together, it should run many more miles than that.

 

Hoping to get to at least 650,000. Not knowing how the truck was driven, or knowing much of the truck history I can only go by guesses and hopes🤣

 

Wow, no tune CP3 kit for a couple grand. Some shop quoted you $5k to install it?

 

Canadian prices bud…it’s $3500 plus taxes on top of that here just for the kit. Plus the shop labor at an average of $200 an hour…PLUS taxes and shop fees…so it adds up real quick

 

Seen it go both ways. 300k original CP4 and 30k on a CP4 kit. Lift pump is a good idea in my book if you have the money.

 

Had an AirDog since 2010.... the motor took a crap mid 2025 and I called AD and asked about their life time warranty. They shipped one to me w/o any questions. I'm a firm believer in companies that stand behind their products! I would put another one into a new truck if I had to!

 

Still trying to understand how a lift pump alone causes better engine drivability on a stock truck.

 

Who says it does? Because it certainly doesn't.

 

I’ve only recently installed the Fass no-drop kit on my ‘11 2500 LML. I chose Fass because it seems to be among the front runners for lift pumps. I only purchased the truck a couple months ago. It has 455,000 kms and still has the original CP4. I’ve replaced the factory injection pressure regulator with the exergy regulator already as a bit of an “insurance policy” but I wanted a bit more protection so I decided to add the lift pump to help a bit more to protect that weak link as much as I can with the hopes I can get a couple more years out of the engine before I go ahead and drop a new engine in it. I’m a high mileage driver, about 80,000 kms a year. She starts the day on the freeway, and finishes the day on the freeway so she gets to stretch her legs often even though during the day it is driving in town.
I already notice that she idles smoother, and at a lower RPM than before, the throttle response is better and smoother and I can’t begin to tell you how much more peace of mind I have knowing I now have constant pressure feeding that pump along with the added fuel filtration that the Fass provides. I don’t consider this an upgrade, I consider this an investment in the improvement of the longevity of the engine….along with very frequent oil and filter changes🤣🤣
End of the day…this is a no-brainer install for anyone wanting to get as much as they can out of their truck.

Who says it does? Because it certainly doesn't.

No, not driveability, but it sure is nice to have when you are changing fuel filters.

Read the highlighted portion of the post above.

FTR, I know damn well it don’t, unless there is something wrong with the lift pump in the injection pump but even then, there would be other issues.

 

Regarding the term "Drivability" and in regards to the OP stating "I already notice that she idles smoother, and at a lower RPM than before, the throttle response is better and smoother". It is certainly within reason that what the OP stated is a result of having a lift pump installed as without one the fuel lines are under a vacuum (suction) and weak/old fuel lines could collapse restricting the fuel delivery (a known issue) and in somes cases seals and o-rings can leak under a vacuum that may not occur under pressure, allowing more air into the fuel lines which if enough air is pulled in,that could also cause what I would call drivability issues.

While the issues I mentioned could be corrected with new seals and fuel lines, these issues would be much less likely (especially collapsed fuel lines) when a lift pump is installed and of course any leaks likely would become obvious. ~BB

 

weak/old fuel lines could collapse

seals can leak

A “maintenance whore” wouldn’t allow these to exist on his truck

that could also cause what I would call drivability issues.

With proper maintenance isn’t the aftermarket lift pump a false fix for these “drivability issues”?

 

I doubt even a maintenance whore pro-actively changes all of the seals and fuel lines that the fuel system has, I wouldn't know exactly what such a whore would do though. In any case and as I mentioned earlier, I don't have these issues even without a lift pump and I have replaced the seals, o-rings and fuel lines inside, to and from the fuel filter housing and will do so again one day when\if needed. Having said that, a collapsed fuel line may be hard for many to detect which again would be much less likely to occur when a lift-pump is installed. Regarding the term "false" fix, I wouldn't use that term as a fix is a fix, but assuming there are air (vacuum) leaks or fuel restrictions, the better fix is to address those items, with or without having a lift pump installed. ~BB

 

Like I said, I LOVE my lift pump. I originally installed it for 2 reasons. 1. After reading over and over that a lift pump might help injectors last longer due to less air / injector starvation and such, I was like OK. Might try that. What made me actually install one was a problem I created trying a new fuel filter in place of the OEM. I bought an adapter for my factory filter head to be able to run Donaldson filters on it. After getting all that done, I started having a problem that was kind of weird. If I was towing on the highway and I stopped for fuel or a pee break or for whatever reason, when I'd get back in my truck, it wouldn't start. I'd have to pop the hood and pump the primer. Only did this when in high fuel usage type situations for extended periods of time (hour +) and if it did it when I got home, I could let it sit overnight and it's start up fine the next day w/o pumping the primer. Anyway, after scratching head over it for a good while, I came up with a theory that the Donaldson filter was more restrictive than the OEM filter and when operating at higher fuel consumption (towing), the CP3 couldn't pull enough fuel from the tank to keep the filter full. It neve ran bad or died, just wouldn't start w/o pumping the pump or letting it sit for hours. I also never had to "bleed" air out when this happened. (never cracked the bleeder), just pump or let sit. My theory was that I was creating a vacuum in the filter and that pumping or letting it sit would refill the filter. The vacuum would eventually pull fuel from the tank while sitting for hours and hours and refill the filter. I had no leaks.

Anyway, that was my real reason for investing in a lift pump - and it solved the problem 100%. I eventually went back to the OEM filter under the hood and added the 2nd filter head back by the tank with the same Donaldson filter some time later -actually years later.

But, as @Ron Nielson said, one of the BIGGEST benefits of the lift pump to me is the ease of bleeding a new fuel filter. Turn on the key, crack the bleeder, wait for the air to stop and tighten the bleeder. All done in a matter of seconds. I change my fuel filter every oil change (10,000 miles). It's not all that often now but back when I was driving 30k -40k miles a year and even when I dropped down to about 23k miles a year, it made a huge difference for an already sucky job. Now that I have 2 fuel filters, it's even better!

And other than solving the vacuum problem, it's never made a noticeable difference in the way the truck runs or performs.

 

Put a Fass Titanium on my LB7 2003 when I got it in 2019. After I changed that fuel regulator up front under everything. Hoping to never change that again. Now after changing a few for friends I've learned the tricks and what is needed and not needed to take off. I have noticed nothing gained from the Fass pump other than better filtration, I deleted the front filter all together because of where it is. Bought my truck from my youngest son who drove it like a mad banshee. Its got 280K now with PPE tune's. Best mod I did was buy a vacuum restriction valve from PPE for the turbo. Now a Fleece turbo intake, helped a bit. 5in exhaust 4in fleece downpipe, and a Wicked wheel 2. My truck does everything I need to do next upgrade will be the 5sp to 6sp transmission and TCM. Transmission will be built up since as it stands now I can push limp mode with the engine now. Also upgrade the exhaust manifolds. Im 60 so this is my last truck when it needs it I will get another H.O engine and put it in. Hopefully years down the road.