The minimum blm scaler value in my bin is set to 84, is that a "normal" typical value ? Seems low to me.
I have experienced an intermittent, very lean oscillation in the off idle, low speed, first gear area with a steady light foot on the throttle.
My WB AFR gauge swings from 14 to 17 or even off scale.
I captured a screen grab from a log file that shows it happening, the blm goes from 84 to 107 back and forth.
This is in closed loop and the INT stays steady at 128'ish

See image:
Surge.jpg

1992 7.4 / 4L80E