There are several tests you can do on the pump to see if it faulty....a pressure gauge and a vacuum gauge is needed.
if the motor COULD run, you could insert a TEE at the fuel inlet and run a vacuum gauge....you should get 3inhg at idle for a functioning fuel pump...or 3 psi at the fuel outlet.
Some tests
Apply pressure to the pulse fitting up 15 psi and see if it holds pressure.....apply vacuum to pulse fitting to 15 inhg and see if it holds vacuum...if it does then air motor side is fine.
the fuel pump side consists of a bellows diaphragm with molded in plastic in the center and brown flapper that seals against the molded plastic.
The diaphragm can rupture leaking fuel (reducing pressure) , and the brown flapper can tear, where it won't push fuel up the outlet.
There are kits online for just the fuel side of the VRO and just the air motor side of the VRO, each about $60....a new non-vro pump is an easy replacement, but will cost you a bit too...about $180...but after the initial purchase I'm sure the rebuilding parts are cheaper.
the rebuilding of the VRO is very simple, plenty of you tube videos, but you only have a finite amount of times you can unscrew the black plastic halves until the threads get boogered up....that too is fixable with some ingenuity.
I'm sure you labeled the fittings or not the fittings of your pump, but
