No start issue

[mongocanfly]

I'm going to abandon the po452 thread..I'm pretty sure it's not my issue
Still cant get engine to run on it's on
Me and PSI have been trying to rule a wiring issue and solve this and I've come to the conclusion that's it's not a PSI harness issue..
What I've done so far
Verified I have 12v key on and crank and have 12v outgoing from the ignition relay
Verified fuel rail pressure, 58psi
Verified 12v at the injectors
Verified harness grounds
Checked fuses
Only code on scanner is po452
Cleaned injectors and verified good spray pattern
Checked injector firing with a noid light..(no fire)
The engine will run if I pour some gas in the throttle
What I've noticed is when I start a crank sequence ,the injectors will fire 1 time..
Then they dont fire again during the crank cycle..
I couldn't see the noid at 1st so I turned the shop lights out, when it does fire the 1 time, it is a very dim light...nothing like how bright they show in the video..but it just fires once during cranking
Gary at psi is thinking it may be in the ecm tune..
The guy I use is hard to get on the phone,,very busy man,, may have to call 50x before he answers..
Just wanting to pick y'alls brains and see if I'm missing something before I call him

Little background
I have changed the intake to the Holley 300-136, mounted the throttle on it with a adapter, the map sensor is integrated in the adapter plate, the maf is mounted on top of the throttle, the cam has been swapped to a btr stage 1
Engine will run, just not on its own