1995 Buick Skylark stalling?

My skylark runs fine but may stall at a light and then I have to wait 45 for the engine to cool down before it will start again. I think it may be fuel related but it seems that a fuel problem would be constant. What puzzles me is that it will start again once the car cools down. It has 71000 miles and it began starting hard about 50000 miles. But sometimes it starts right up. hmm?