Hi,

Basic fuel pressure is 3.5 bar. (running engine and hose disconnected from regulator or fuel pump running alone)
If you are on idle, inlet pressure is - 0.8 bar (common value) and your fuel pressure should be 3.5 - 0.8 = 2.7 bar
If you are on charge, ie with stage 1 EPROM with 1.1 bar TC pressure, your fuel pressure should be 3.5 + 1.1 = 4.6 bar.

Regards.
Claude