Jake brakes very rough

[Chamberpains]

This may not be what is being described. But I'm throwing my experience in to the mix.
My CM870 does this fairly often. I current engine has brand new solenoids, overhead is done recently, the engine is reman'ed Cummins 200,000 miles, turbo is YTS new, jake harness wiring checks out and no oil in the pass through connector. My last engine with from 750,000 to self destruction at 1.1 million did the same.

As long as I've ran an ISX it has always done this. Especially after long low boost cruising. I've come to just live with it. Its choppy maybe better described as fluttery til I cut them out with the throttle and let them come back on, then it smooths out. If I let it stay choppy and keep "jaking" it'll smooth itself out but feels funny till it does. I've always taken this as one of those "nature of the beast" things. I could definitely be wrong though. Maybe the engine gods have more insight??