Turbo boost surging while in cruise.
So while driving back from Michigan today my 350 Cummings dip started to surge. I would be in cruise at 65 and the turbo boost gage would kick back and fourth and I could feel it in my seat. It felt like the engine break kicked on but it never would slow down. If Cruise was off it would not do it. It did not do this at all on the previous 8 hours of driving.
I did just fuel up so I wonder if I got bad fuel? If that is the case why is it doing this only when cruise control is on?
Any ideas anyone? So far online searches have not come up with a lot of answers even from the professional driver forums.
2001 Monaco Diplomat