fuel pressur will not go back to 0 on my gauge if i open the bleeder screw on the isolator it will go back to 0 then i restart the truck it goes to 8 psi and stays there and it will keep going up evry time i start it or slowly rise as i drive it the dealer just put a new FP and IP it was fine for the first 800 miles or so and then started doing it is there a check valve that might be stuck

 

Isloators are notorious for failing. Looks like you joined that club.
IMHO you are better off ditching it and running it direct.