Trying to keep this short:
6 days ago, wouldn't start at all (crank, but no start)
FCIM volages check OK
Used a straight pin stolen from the wife to poke into the back of the ICM connector (stripping wires is silly) so I could watch it how it was working. Voltage got up to about 0.6V (below the 0.8V needed for a start).
The wife's car had a problem, so I had to fix that first, then today (6 days later) I got back to the Truck. The damn thing started right up.
When it was warm, holding the motor to about 2500 rpm, it started to produce a plethora of white smoke, but when I put it back to idle, the smoke stopped.
What the heck is going on?