I just got a 2004 f250 with 260k on it. It has a strange hard start issue. Sometimes it will do it when it's cold, sometimes when it's hot, and sometimes not at all. Sometimes it will take a couple cycles of the key cranking for 10-15 sec and it starts, other times it will take 10 min. I just changed the icp hoping that was it, but it didn't change things.

 

Need to check all the values such as hpo system, fuel pressure, ficm voltage, battery life.

 

Check for loose connections and chaffed wiring on any gage or control system. Other than that, you'll need some gages to help isolate the issue. There are ways to check with a multimeter, but for the cost of a good meter, you can read live data (assuming you already have an android device).

Invest $30 in Torque Pro (Android App) so you can read some live data. You could also spend ~$150 on Scan gage II. Right now your shooting at a 300 yard target with iron sites. Live data gives you a 7x scope to narrow the search down a bit.