it is an ignition control module inside the distributor. i had the exact same problem. car would run great sometimes and sputter others and die all together sometimes. you cant buy the part from the dealer or any parts place though. i had an old distributor laying around and i swapped it from there and it fixed my problem. i garuntee if you get another good distributor your problem will be solved. also the wrong ecu wouldnt do any damage it would just be a lot slower. you can jump at least one tooth on your timing belt and not do any damage but the car will run really bad i have had that happen also.