Engine will not start?

I arrived home one day and parked my truck in the driveway, the next morning I attempted to start the truck and leave, at that point the truck would turn over but would not start. I first thought it was just out of gas so I put some gas in but it still would not start. Then I thought it might be the full pump so I attemted to prime the carberator with starting fluid and then some gas but still would not start. At that point I replaced the ignition solinoid, rotor, distributer cap and plug wires but it still will not start. When I attempt to start the truck I do smell gas so I do not think it is the carberator. I do not think there is any spark getting to the plug wires. I do periodically get a code on the digital odometer that sais " NO BUS". I have asked several people but knowone seems to know what this means. Do you have any idea what my problem might be. Thx randy cornett buckeye, az