Your ECU is doing its job. It's supposed to maintain an idle speed around 750 RPMs. 750 RPMs is between 650-800, and that's why I've told you twice that you're wasting your time on that screw.

If you close that screw down, the AICV opens more. If you back the screw out, the AICV opens less. All that screw has to do is get your idle in range of where the AICV opens and closes. There's no way for an end user to check it.

If your idle is giving you this much trouble, why don't you let a mechanic look at it? It doesn't sound to me like your idle is off.