Im ignorant of how the Diesel Fuel system works, please explain and discuss how to upgrade it . Thanks-TIM

 

Isn't the lift pump just like a normal fuel pump? I don't know much about diesels either but, I think it just gets the fuel from the tank to the injection pump.

 

The fuel system in the dmax trucks has no pump between the tank and the cp3 (main injection pump on motor) The system with stock programing has no problems pumping the fuel the whole way, but when you start adding programmers the cp3 can't keep up and you start running out of fuel and sometimes throwing codes. I am not 100% sure with the LBZ, but the LLYs will throw a p1093 when the truck runs out of fuel. What is actually happening is the fuel rail is drying out and falling below the proper pressure. Alot of people are shimming the refief valve on the fuel rail and fixing the problems, but when you start adding more fuel (bigger programs) you will want to add lift pumps. The system was designed to use a lift pump, but gm dropped it from the design so some people say that even a stock truck will notice an improvment with one. The pumps go inline between the tank and the motor and add about 12psi of pressure ( dont quote me on the pressures ) The Kennedy pumps, as well as TTS are flow through, so if they were to take a **** the truck would still run.

I added the twin pumps from Kennedy on my truck and noticed a difference right away, mostly on the top end. Before I got EFI live I was running a Predator and there were times I couldn't even pass on the highway with out throwing a code, now I can be going 80mph with a much bigger program and pour smoke while passing on the highways without a problem.

 

I have the KD pumps on my LLY and an Aeromotive A1000 feeds my twin CP3's on my LB7.

Definitely a must have for performance and it also keeps air out of the system as well as allows for all of the fuel filter media to be used rather than just the bottom third.

 

Thanks Guys! That helps a ton. Looks like a lift pump will be one of my next mods.just running this mild hypertech im ok, but the next round of tuning is going to need more fueling. Thanks again, great info.

 

There is a mechanical pump that mounts under the hood called a MITUSA pump. It works well also. I run TTS twin electric pumps, but would have the MITUSA if it was out when I bought my pumps.