Ok I have the problem figured out I think.

Can someone tell me if I understand the system correctly…..

Ok the pressure switch boost air pipe trigger switch in picture number 20.

When boost hits 15 PSI the switch grounds the switch over valve picture # 21

This in turn cuts the pressure to the ALDA picture # 14 and stops sending extra fuel to the pump.
If this is all correct, I have a bad pressure switch boost air pipe trigger switch in picture number 20 because when engine is shut off it is still grounded at the post….