My truck has startd doing something strange. I parked on a slight incline (front of the truck pointed uphill) one day at work with the fuel guage on E. I cranked the truck to leave and put it in reverse and it died. Went to restart and it would not fire. Hand pumped fuel to check for air, no obviuos air bubles. Tried cranking again for 30 sec to one minute and she fired up. This has happened twice more, once with low fuel and once with a quarter tank, all with the truck pointed slightly up hill. The truck is an 06' 4x4 duramax. It has a diablo programmer on a medium setting. Anyone have any ideas of what is going on. The truck has always restarted, but I have to turn it over for a while before it will start. Thanks for the help, JS.