I know you say you have cleaned the IACV. But it could be sticking. I struck this once.

Have you got a known good IACV you can swap ?


I can't remember that engine as it has been a while. But if I recall you can try unplugging various items to see if it influences the drive.

IE unplug the IACV and see if the symptoms disapear. It wont run great like this. Also if I remember you could do the same with the EHA... Not sure if this could be related though.