Intermittent engine miss like engine timing.

My 7.3 has 67K miles and started missing like the timing was off a couple of weeks ago. It is worse in the morning and seems to miss less after it has been running for about 15 minutes. I get a service engine light. It cleared up after a few days and the check engine went out. It started to miss again and would start to run smooth and then start missing again. I cannot seem to find any connection to something that I am doing to create the problem. It starts quickly in the morning but has this miss. It seems like maybe a wire is loose or I though maybe the cam sensor or glow plug relay might be causing it but I need help!!