I may not be right, but if the FCD has been correctly installed it sounds very much like ignition breakdown. My car had exactly the same problem which was solved with the replacement of the ignition leads. The change was dramatic, as the effect had been as if I was hitting a fuel cut/rev limiter. I had tried everything and the replacement of the leads was the last resort. You can source leads from TopGun for about $87. If this is the problem can you please let me know.