After we bought some diesel at the gas station the truck would not start. It just turns over. We changed the fuel filters a week ago and bled them. The truck has for run well over an hour since then and was running fine. We opened up the bleeder valves on the secondary and final filters and there are no air bubbles coming out and we can hear the fuel pump. Maybe air got past the filters? The fuel shutoff lever and throttle seem to be operating properly as well. The tank was low on fuel (1/8 of tank) and we had to go down a steep hill to get the truck stop, but it was running smoothly when we shut it down. I did not have much luck with searching and we are in a hurry, sorry if this has been covered before. Any suggestions would be appreciated. Thank you