why does my car start and stop suddenly?

Dear Ali-- Your question takes one sentence, but an answer could takes many pages and chapters even. Your 1990 Camaro starts and stops suddenly because you have a clogged fuel filter, a dirty air filter, some bad wires or faulty spark plugs, a bad PCV or EGR valve, a fault Mass Air sensor or Oxygen sensor, bad fuel injectors, etc. etc. See what I mean? If you are not a trained mechanic, find a good one and have him take a look at your car. Despite the many possibilities, you should be able to pinpoint the problem fairly quickly with a hands-on diagnosis. Good luck from Bovan.