when you fitted new FMIC did you fit new dump valve, only i have seen certain dump valves on FMIC set up cause high and irregular tick over, when dump valve changed the fault went.
Another thing to look at is idle control valve, may be sticking, when tick over is high give the valve a light tap with the handle of a screwdriver. I had this with my idle control valve and if i tapped the valve the idle would drop. Cured it by changing the valve.