My quick guess is either ICP sensor or FICM issues. Check this out and see what you think... Diesel Technician Society
Also I know the article says for 03/04 trucks, the only difference is the blurb about the oil doesn't really concern you since 05+ trucks the ICP sensor is located on the passenger side valve cover. The issue with the starting problems still concerns you though. Have you tried to get codes read on it? It might still have some codes even without a check engine light.