That is correct, when the FPR is manifold-referenced then the B4001 IFR table is flat "static" like you said...
(manifold-referenced FPR requires a return line back to tank)
Do this:
- with FPR exposed to baro (i.e. reference hose removed) and pump running measure rail pressure,
- calculate IFR for your injectors using measured rail pressure using the spreadsheet,
- populate all cells in B4001 with the MANVAC=0kPa IFR value.
See this (link to spreadsheet):
showthread.php?t=4821
The manifold-referenced FPR adds MAP to the regulated pressure, thereby keeping the pressure
difference across an injector constant (i.e. rail pressure on top, MAP below).