Have a dramatic RPM surge going on at specific engine temps as the car warms up.

COLD ENGINE: no problem; idle correct, smooth

WARM ENGINE: ICV will suddenly (and i mean SUDDENLY!) open so that the idle in neutral jumps from 500 to 1300. If in D, stopped at a light, risk of suddenly jumping into the car in front. Idle will stay high for a minute or 2, then slowly go back down to 500. Problem may repeat as engine warms further.

HOT ENGINE: No problem; idle correct, smooth.

Checked MAF connector for voltage: OK. Checked it for resistance: OK.
Checked ICV connector for 12Vdc: OK. Checked ICV resistances: OK

I have no idea what sensors (or the computer) could be sending a bad ICV signal to cause it to open. Again - this ONLY happens as the is warming; not when either cold or hot.