When I did the 520 mod on Donkey I ran into an issue, I had the shift position switch clocked wrong so it was showing "-" on the dash. It would crank & I had spark but the fuel injector wasn't pulsing. Once I cleared that fault it started. I was able to get it to fire by before clearing the fault by spraying carb clean in the throttle body. There may be a DTC thats preventing the injector from pulsing.