For time being, don't connect the vacuum pipe on the pressure regulator to anything.

Disconnect everything you can from the breather system etc and block off all the openings until you get it running to eliminate as many air leaks as u can.

If you are not running an amal valve just take a pipe from the compressor housing to the actuator and make sure the return pipe on the base of the metering head is blocked off.

These are all air leaks if left open.