losing PSI
 

Long story short, I'm trying to track down a hard start issue. I think I've got it narrowed down to a fuel pressure problem.

Stock 06 lq4 in my Silverado.

Key on - 58-60 psi
Running - 58-60

It seems like it holds at 55+ for a while. Left the gauge on the other day and it dropped down to 40psi in 45 minutes.

How much leak down is too much?
Should I pull the rails and see if injectors are leaking? If its jot injectors, that only leaves the pump/regulator assembly, right?

Normal

Well that's a bummer... Guess I don't have it narrowed down anymore. Haha