cp3 question

[nspence]

I have a 2005 lly now I'm thinking my cp3 is weak. Truck won't start I've done everything from whiff delete rebuilt filter head new fuel filter . Now when I took the return line off the cp3 and primed it fuel came out slowly . Should fuel come out of. There just from priming the sytem

 

[nspence]

anyone ?

 

[Dirty_D]

You need to get your hands on a quality scan tool like a snap on and look at desired fuel rail pressure verses actual. Could also be a bad fuel pressure regulator. CP3's early go bad. Are there any codes stored?