The best solution for any FI car is proper tuning... I'm not completely convinced that you don't haver a mechanical problem though. I know those FMUs (as well as all FMUs) suck ass. Make sure you've got a good solid vacuum system (you could pressure test it if you wanted to).

Can you post a pic of the dyno graph?

You should considera standalone EMS... you can get great dwals on them now, and its much cheaper than rebuilding your ITR... where are you located?