Duramax engines are one of the most responsive engines to an aftermarket lift pump. The reason is that these engines don't feature a lift pump to help them supply fuel to the engine. In fact, the engines rely on a CP3 or CP4 pump to pull fuel from the tank to the engine.
At any rate, do I really need a lift pump on my Duramax?
The GMC and Chevy Duramax pick-up trucks do NOT have a lift pump to supply fuel to the engine. From the factory, the CP3 injection pump is the truck's only means of getting fuel from the tank to the engine. ... For example; The AirDog II, FP100 and Raptor pump kits do not require you to drop the tank to install the system.
Just as much, how big of a lift pump do I need? As a general rule of thumb, for most Duramax, Cummins and '08-current Power Strokes, a 95 or 100-gph kit will support 500-to-600 hp, a 150 to 165-gph system will handle up to 800-to-900 hp and a 200-gph or more pump can support north of 1,000 hp.
Further, will a lift pump make more power?
More Power Most lift pump companies cite superior water separation and better supply pressure as reasons to purchase their product, but in most cases, a higher-pressure lift pump can add power, too.
How many miles do Duramax last?
Most reputable organizations, such as the Association of Diesel Specialists, would agree that the 6.6l Duramax is one of the most reliable diesel motors available today. Provided proper maintenance, it can easily hit the 350,000 mile mark, with some users claiming 400-500,000 miles is the norm.
It's the electronic side of the transmission sensing excessive slipping and placing the unit in fail-safe mode, where only one forward gear is available. As you've probably deduced up to this point, the stock Allison will handle roughly 350 to 400-rwhp in five-speed form and 425 to 450-rwhp in six-speed trim.
Changes included a Borgwerner Variable Geometry Turbocharger, the addition of an in-tank lift pump, and a fully-functional hood scoop. A 6-speed Allison automatic transmission was also used until 2020.
The purpose of a lift pump is quite simple: to provide fuel to the injection pump. The fuel doesn't need to be under high pressure (that's the job of the injection pump), but it does need to support the volume demands of the injection pump, which relies on diesel fuel for lubrication.
The cummins CP3 will run without a lift pump also, the same as duramax. Dodge or cummins decided they wanted an easier way to prime the fuel system after filter replacement that's what the lift pump is for. If the lift pump fails then there is too much restriction for the cp3 to suck fuel through so the engine dies.
First sign of a bad lift pump is if you have trouble getting fuel back to the engine after changing the fuel filter. The CTD will still run with a bad lift pump but will be very hard to restart if you ever loose prime. You can also check the fuel presure at the rear of the filter, it should be about 15 psi.