Update,

I disconnected the AFPR and hooked directly into the return side of the fuel rail. I started the pump and after about 5 seconds, no more bubbles appeared. it was a clean flow of fuel with no air. Now, I am not sure if what I am seeing out of the outlet side of the AFPR is normal or not. Any ideas or info is appreciated.

Thanks,

Oscar

I don't even understand what you're trying to test. The AFPR is the clamp in the system that sets the pressure, and the diaphragm/spring combo allows the pressure to vary up/down with the reference air source.

Have you tested the fuel system (CLOSED!) and verified the boost pressure (air source) forces the fuel pressure to rise in a 1:1 manner? You can log this with a cheap linear sensor via ECMLink. Now.......even if it tests in a beautiful curve 1:1 manner, don't be shocked when your fuel pressure curves while driving/logging are a jagged mess, especially with very large injectors. And to the earlier point.....is the diaphragm blown/ripped?

"Cranking takes longer than usual and 'whoops' " ..........doesn't give me any confidence that the problem doesn't lie elsewhere. It's clearly pushing fuel, at least during the conditions of your test.