I called a diesel injection shop and asked what the internal pump pressure should be for my pump 0 460 484 027 and was given these numbers:
5 to 5.5 bars (72.5 to 79.7 psi) @ 2500 RPM (engine ). This translates to 32 psi at 1000 rpm (assuming pressure is linear), which was what my regulator was at before I started messing with it!
I understand that you got the spec @ 2500rpm, but you never mentioned a spec @ 1000rpm.
-Todd