larry30000

Running the Quad XZT on 3 wot fuel pressure drops to 0 quick, but the rail pressure stays between 24,000-25,000. I know I will need to up grade the lift pump. In the mean time will I hurt anything running hard on level 3?

tritont

the fuel helps cool the CP3. If you're at zero pressure, there's likely a much lower flow rate which in turn would put stress on the CP3. The CP3 also like positive pressure, it's doesn't have to be a lot....just there.

IMO, I wouldn't take the chance at ruining a 3 or 4K pump and do the lift pump asap if you're going to continue running it like that.

05CTDN8

I remember reading somewhere that cummins recommends no less than 15psi at any time to the CP3. Makes sense that DC would run it at 9, means more warranty work....

shortbed rv

samething happens to me. My boost hits 39 psi about the same time as fuel drops to zero. I just back off. I plan on a fuel system upgrade but I will still have the high boost pressure.

larry30000

My boost only hits 27-30 psi.

shortbed rv

larry I am just thinking out loud but I think perhaps we tapped differentily for the boost reading. Perhaps I am getting actual boost and you maybe getting the results of boost fooling. Then again I maybe wrong? I have heard of a 03 getting 37psi. Lets see if anyone else jumps in with their boost numbers.