92 olds cutlas 3.3 240k starts runs for about 20 min and dies.has to cool down

A few things can cause this issue like a bad fuel pump or crank sensor. In the interest of saving money and not guessing at parts to throw at it, I suggest a diagnosis at a shop. We would be guessing without having a chance to look at the car. If you want to do some basic diagnosis start with checking for fuel pressure when it dies out. You can rent a fuel pressure tester at most auto parts stores for free. If you have fuel pressure then check for spark. https://repairpal.com/repair-shops Alex