C15 6nz Motor dropping out.

Trying to figure out why my truck is doing this. It is a 2002 Peterbilt 379 with a built C15. The build was 3 years ago and has ran great up until now. The build is a marine cam, marine injectors plus 10%, with an 80mm turbo and a 650hp tune. The dropping out is occurring when on the top side and under load while making boost. I will shift a gear go full throttle make about 28 to 30psi of boost and then it cuts fuel all the way to 0 boost then it picks back up. This happens back and forth. Really not sure why it's doing this and have replaced alot of parts and checked over many other parts.

 

It does it cold or warmed up. The overhead was ran and the Jake's are turned off during this video.

 

This problem started 3 weeks ago. At the beginning of it I pulled the valve covers to make sure everything looked good in there. I found a cracked brake housing. Could not find a Pacbrake replacement and replaced all 3 with Jacob jakebrakes. I ran the overhead when I replaced them. The following week I had the truck looked at by the engine builder at that time he found the charge air cooler leaking. I had him replace it and rerun the overhead to be sure it was adjusted correctly. Brought the truck back home put a light load on it and ran it. Seamed to run fine. The next day I put on a 40,000lb load and was still acting up. After that I have replaced the cam sensor, crank sensor, boost sensor and the fuel check valves. When I replaced the check valves it amplified this problem and now does it all the time on the high side of the transmission and building boost.

 

I tried to put a meter on it and couldn't figure anything out with it.