dmax woes. won't start
 

having problems with my truck lately.
had loping idle. replaced the FPR with new stock bosch fixed that issue.
truck would stumble on acceleration, replaced FPRV fixed this problem.
truck has airdog lift pump, new stock filter, all new orings in filter housing.
truck has fuel pressure at the injection pump. all injectors bal are within tolerance.
I drove the truck for a week with no issues. now won't start.
diablo sport shows low rail pressure.
any ideals?
2004.5 lly

Manually check your fuel pressure at the rail. Might need a fuel filter and or pump. Any engine codes?

check

Prime. try re-priming until bulb is hard

cranking RPM, batteries

injector return rates

CP3 return rate

anything else done to the truck? Mods?

truck has airdog 100
 

the truck has a airdog lift pump and shows about 9 psi.
truck started fine the next day and has been starting fine the last few days.
injector balance is within spec.