2001 Ford F-150 • 158,000 miles

The truck misses while trying to drive it but if you have over 1/4 of a tank of fuel it runs fine. I have changed coil pack numbers 5, 6, and 7. It has the 5.4 in it. Also the hole where the spark plug and coil pack has water in them. I think in may be something to do with fuel thought because of the amount of fuel part. Any help would be much appreciated.
October 22, 2013.

Have you tested the fuel pressure at both tank levels? If not I would suggest doing that.

Oct 22, 2013.