When doing a full proof test the injectors would be unplugged meaning that they couldn't(hopefully) have any influence on pressure generation.

After build up of pressure on cranking there should still be a natural decay of pressure when you stop cranking even with the injectors unplugged. How does the pressure decay compare to your known good capture?

When you say pressure can only be released manually, do you mean litteraly crack off an injector pipe or unscrew the frp sensor?

I suppose this is a good time to have the high pressure gauge (spoke about in an other post today) to check the sensor isn' telling porkies.

James