i just bought a 93 si yesterday and the only problem i could find was that it would almost die when i had the ac on and was idling. the car sat for about 9 months before they got it ready to sell. if you need any more info let me know. thanks

 

have your ignition timing checked.

 

your throttle plate/body and Idle air control valve may be gumed up or carboned up. Spray everything out with throttle body cleaner and see if that helps and check your ignition timing.