I check the management system (before to many times) testing with original Ford FDS 2000 (live-road testing), and was fine. The mass air flow meter signal was ~4,55-4,65volt(1,4bar overboost, 5860RPM in 4.gear 190km/h, WOT, wide open TPS)
The Ford EECIV theory is for mass air flow meter: max volt 4,75volt, higher signal is wrong, and will get some fault code.
All signals, sensors looks good with FDS tester (I tested separetly MAP sensor too, and Ok.)