Hi Tony
I am using just a SP fuel pressure tester, not in the fuel line but there's a valve on the end of the fuel rail. I now understand that the fuel pressure will not beable to get above 3.5 bar becuase that is the lowest rated regulator in the system. So if i blank of the fuel line before it goes into the fuel rail, and measure the pressure it should tell me what the other regulator is doing?

Regards Jamie