Water accumulation in diesel, especially since the introduction of the new ultra low-sulfur blends, is very common. You have a fuel/water separator which needs monthly maintenance and draining. If not drained properly, it can allow water to get into the fuel rails and this can blow the tips off injectors. Ford has issued a directive to dealers stating, signs of rust in the fuel rails are a sign of water and will not be warranted. They've actually advised dealers to let customers know this and quote a complete fuel system replacement at around $12-15K. You fell right into this. Have you ever drained this separator system? The link below is good...especially starting with Post#7.
https://www.ford-trucks.com/forums/1...or-on-17s.html
Thor Forums
