what is wrong ---- help

i have an 96 alt with about 130000 miles on it. one day last week i parked my car, went in the house everything was fine. but when i came out and started it, it started missing, had no power, put it in drive will not move, hit the gas and it cuts off, start it up again and it misses hit the gas while in park and it dont want to take the gas but run very bad, put it in drive it runs but when i hit the gas, it cuts off. now if i let it run for about 2 to 3 min, the missing will clear up, the car has full power, can put it in drive and take off, but this only last about 45 sec. then back all over again. if i let it sit there another 2 to 3 min , then full power will kick back in, and i can go down the street full speed. whats wrong?

pull put your spark plug wires and see if they are oil soaked from the valve cover leaking

pulled all plugs and wires, no oil leaks, went got new plugs, wires, oil and filter, fuel filter, air filter, and drained my gas and put in some more. Still the same thing. Can this be my timing, computer, or some sencer?