Ok, so sometimes I as I am pulling up to a light the truck dies, then according to my Quadzilla gauge the fuel rail pressures are between 3K and 4K no matter how hard I floor the accelerator, and the truck really lacks power. This is an intremitent problem as it does not happen all the time.

Does anyone have any ideas??

So far I have drained the fuel water separator and just found a couple little bubbles of water, nothing much, I also replaced the fuel filter.

 

I'd say the first spot to check is your lift pump. If it's dead, you won't get a reliable supply to the CP3, which can affect your rail pressure.

 

As said, check lift pump pressure and it could be a faulty FCA valve. Have you tried checking for codes with a scanner?

Also, is the quad gauge one of the original rail pressure gauges?? From when they first came out?

 

No I just got it a couple of weeks ago.