hi might be a little more help if you can post engine code
wonder if the fuel isn't getting back to the tank from the return might be a kinked pipe on the return.
could also be worth checking 3rd piston wiring.
as well as fuel pressure sensor wiring IE supply ground etc. Don't suppose its over charging from alternator or the fuel pressure sensor wiring is short to supply.
my only other thought would be mass air giving an incorrect reading there for not using fuel for engine speed. hope this makes some kind of sense.
question mpa??? not another conversion required to make sense of pressure why cant they find a common measurement and stick to it