I have a 97 Chevy cavalier 2.2 and I was driving it one night and it just stalled it trys to crank over but it won't start. I had a friend look at it and he said it has spark and the timing looks fine. I just replaced the cam shaft sensor and the crank shaft sensor. and still have the same problem. Someone said it could be fuel pump but I can hear it turn oven when I turn the key. What can it be.