It's not for a specific starting problem but it's planned for maintenance of "C"-Check.
I see in TO for test of Start Valve, with a inlet pressure of 150 PSI, max regulated air pressure is 42 PSI and the mini 36.5 with inlet pressure of 45 PSI.
Not in In/Hg, sure.
We can't have a regulated pressure superior at the inlet pressure.
But actually APU provides a inlet pressure between 30 to 35 PSI, what is the regulated air pressure ? More precisely in the pressure sensing line.