What could cause my truck not to start on some occasions. The battery is fine and cranks but wont turn over at times. This is very random and I usually would wait ten or fifteen minutes and it would start. The frequency however is getting worse and the time to wait for it to start can be over an hour. This problem started about a year ago and would happen twice in a month. Now it does it at least twice a week. I called the chevrolet dealer where I purchased it. I bought it new. I was told it would be better off for it just to break down rather then do a diagnostic that would be costly. I really dont wont to get stuck on the road. Can you give me any suggestions on what could be causing this. The truck is a 4x4 5 cylinder. There are no other problems with the truck.