1990 Pontiac Sunbird SE cranks but wont start

1990 Pontiac Sunbird SE, 83,000 miles. My car seemed to run well enough the last time I had used it. I did not drive it for about 4-5 days. It was difficult to start the car after that. It would crank a lot when I turned the ignition but would not turn over. In order to get the engine to turn over, I had to keep the accelerator pressed to the floor (similar to what would be done with a flooded engine). When driving, the acceleration was very poor and there was a soft, metallic rattle. Whenever I stopped the car (such as a stop light), the engine would stop and I would have to go through the same startup routine as already described. I parked the car for several hours and when I tried to start it once again, the engine did not turn over despite my best efforts. It would crank but nothing more.