WOT fuel pressure bleeds down, if i turn the engine off pressure holds, but at WOT it goes up 41-43 and bleeds down instead of rising which is causing a hesitation. Car was running fine until this popped up out the blue. I have replaced injectors with another stock set, opti new, fpr new, fuel pump is new,fuel filter has been changed twice, fuel pump assembly fine.

 

Still sounds like the pump can't deliver enough fuel.

 

Agree. If the fuel filter is good, I suspect the pump itself is giving out.

Rich