At moment I'm trying to figure out why I'm losing fuel pressure once engine bay heats up(10-15 min driving)It's only small decrease 5-6 psi but enough to change Afr.
Plus doesn't hold fuel pressure after priming system.just drops to zero quickly. But car starts fine.
I've only just ran new fuel lines,injectors, rails, fuel pressure reg, fuel pump, fuel filter.
There's no fuel leaking anywhere. Doesn't sound like any vacuum leaks and manifold pressure looks about right.
I've changed pump back to old walbro. Still same.
I'm thinking fuel temperature is getting higher than normal, dropping pressure but that's just a guess. Fuel lines does have aeroflows silcon protection tubing.

Has anyone had this problem before. ???