Any experience with 380hp mpfi conversion kit?

Never messed with it beyond my 99 Durango. Not an expert but for conversation sakes, if it fires and runs briefly that tells me the pump is priming and you’re getting ignition. It almost sounds like it’s not getting crank signal to the ecu so there’s just the initial prime shot of fuel with no fuel pump past that. Easy to verify fuel pressure. I know not much help. Just my thought. Maybe draw some attention to your post from others that do know.