Sorry for the delay
I removed the fuel pressure regulator, piped to compressor and turned air regulator up until the fuel regulator started to blow off at 3.5 bar.
So all looked good....or so I thought!!
I placed the regular in a basin of water at 2.5 to 3 bar. The air from the compressor was escaping through the vacuum port.
Therefore, when the regulator is working on the fuel rail, some of the excess fuel is entering the engine via the vacuum hose!
Anyone out there selling a fuel pressure reg!!
Thanks for the help again,
Dave