BTW, I don't know if this applies to Acuras but, I went through IAC problem on my '97 Mitsubishi Eclipse GST. Dealer wanted to replace valve for $300 plus. Turns out there is known problem with idle adjust screw losing its locking cap and backing itself out. A few turns of the screw and some silicone to lock it and problem solved. IT seems the screw gets so far out of place, the IAC servo loop can't make any sense out of the readings it gets and the servo position, so it hunts and idle goes up and down. Mybe this applies somehow to hondas/acuras too?