A similar thing happened with my 90 Beretta! Turns out it was some kind of censor for the transmission...it would kill it when it would hit a certain point. Basically they pulled the censor and it stopped stalling. That was 2-3 years ago. (supposed to be a temp fix until i could get it replaced FYI) I should mention though that now if i drive it at high speeds (75-80) for more than an hour and then come to a stop it will idle rough and want to stall so i throw it in neutral and keep the RPMs up. Hopefully this is helpful!!!!!