As far as I know, the pressure regulator only lowers any excess pressure by opening and sending the extra fuel back to the tank. The pressure at the injectors should be approx 35 psi (don't remember the exact number).
Injectors are between fuel pump on the sender side and pressure regulator on the return side to tank. So what is specified is the pressure on the injectors. On the GTV 6 the pressure is 2,5 bar at normal operation and its lowered to 2 bar at idle. The regulation is via air vacuum hose to the fuel pressure regulator in front of the fuel rail.
The regulator maintains a constant pressure difference of 36 PSI between the fuel rail and the intake manifold. The regulator should hold the rail pressure at ~36 PSI with the vacuum hose to the regulator disconnected. If the vacuum hose is connected, the pressure in the rail will be lower by the amount of vacuum in the intake manifold.
e.g.: if you're running 4 PSI of vacuum, the pressure in the rail should be 32 PSI with the hose connected.
tested fuel pressure and with vacuum line connected 35,disconnected 30-40 psi.so that's good.then went to vacuum.steady idle 10-12hg.no good.must be 15-20 hg.so tommorow i'll advance the timing a bit and see.