1994 Pontiac Firebird Engine died

I got my dads 94 formula about six months ago and it had been setting for a year berfor I got it. When I went to pick it up it ran fine for a week then the cluch and water pump went out. It was in a repair shop for four months then I got it out. I drove it for about two weeks then the engine died on me as I was driving to dallas. I had already chaged the oil, cleaned the air filter, intake and changed most of the fluids in it. When I took it to get the inspection, the only problems with it was the brights. When it died I was on an overpass and shifted in to 5th. I stepped on the gas and the engine just lost power so I whent to fourth and it lost even more power when I stepped on the gas for a second time and stopped running. Then it wouldn't star again. I don't know what the problem is!