Kobelco loss of power

This might get a bit long but I want to include all of the details.
Kobelco SK200Lc Mark IV. 5.9 Cummins. A couple hundred hours ago the engine started to surge at low idle. If I bumped up the rpm's a couple hundred revs it would be fine. It seemed to be worse when it was cold or when I first started it up. It had good power and no other issues. All new filters and some fuel additive but it still surges at very low idle. New fuel shut-off solenoid about 700 hours ago.
Now within the last 50...

Kobelco loss of power

Kobelco loss of power