Saturday my 1993 850 GLT refused to start. It would turn over but would never catch. I then pressed the gas pedal and it ran very roughly for 30 seconds and then died. Further attempts were fruitless and by then I could smell gas. Several hours later I tried it again. The starter would crank but the engine would do nothing. I had it towed into my Volvo mechanic where it sat until Monday. Monday he called and said the car started fine for him. He said there were no error codes as well. He said maybe it was a fluke. I am worried it is going to happen again and leave us stranded. Any ideas on what to do?