Crazy surging. Had me stumped.
 

Throwing a 216 code " injection pump timing control circuit. I have not checked fuel pressure yet. But if someone could tell me in simple man's terms what this means I would certainly appreciate it. Thanks in advance

216 can mean bad vp44 like the computer board is jacked, bad rotor within vp44 but can also be just low fuel pressure from the lift pump. Try going to blue chip diesel and do the vp44 pump diagnostics
https://www.bluechipdiesel.com/vp44_diagnostics.html