I followed the FSM procedure the other night. Can't tell you if the 41 is really good while running. (It'* about what I get idling.)
Correct test is turn car on on (not run), bleed out air. Turn key back on and watch pressure. Cycle car on as needed to obtain max pressure.
If it leaks down as you mention use a shutoff valve to determine if it'* the injectors or in the tank.
My assumption is if you cycle the ignition enough and it leaks down, you would get a poor start if the injectors were flooding a cylinder or two.
Acceptable range for fp on the test is 47-52 I think...(don't have manual in front of me.)
00 Regal GS: All kinds of cool stuff.