I adjusted the idle control valve.

I opened the valve up four turns.  The off idle stumble disappeared and it
revved easier with the throttle being open slowly in the first part of rotation
of the butterfly valve.

The ICM and the ECM hand off to each other control of the engine when off
idle and up to @1500~2000 where it is like a midrange circuit on a Carb.

I did not check the O2 readings, but will later.

I am running a modified cam along with other changes.

If you decide to adjust this, you are at your own risk.  Just remember how
many turns you made so if you need to put it back you can...

Robert