Just as a side note Assassin over at the netreg site there is a "recall" section that has some info and a better source is over at ZR1Specialist.com, Marc Haibeck's site.....he has a fairly good explaination of the PROM programming...at least Marc's write up was enlightening to me but I'm new to EEC!
I bought the update for my 90 as it still had the original version...net result was a bit better but the idle speed still "hangs" upon de-accleration but not as long as it did with the original program. I think, if I understood Marc's explaination correctly, that the idea was to use the program as a de-accel valve without actually having a de-accel valve. Something about emissions upon engine de-acceleration being too high or some such thing
Tom