2002 Cavalier No Start Problem

Got it my car to leave work several nights ago the car cranked normally but no start at all, tried this several time then gave up. No smell of flooding and tried swapping the fuel pump relay, no change. Came back the next day and the car started normally, I ran it for a bit shut down and it re started once again. After sitting for several hours I tried it again and the problem repeated ( crank but no start ). Had the car towed to a local mechanic who claims he found a short between the computer and the fuel pump, car then ran without incident for the next several days until yesterday when I came out of a local store and the problem resumed. Any idea's appreciated..

I would be very suspicious of the fuel pump. If it happens again, try banging like hell on the fuel tank underneath the car while someone else cranks the engine over. If it starts, it's the fuel pump causing the problem.