A friend's 2002 F-250 7.3l, 204,000 miles, stopped on him yesterday. No warning. After I got there we "checked around" to no avail. The water drain valve at the filter was opened, and when ignition was turned on, a good flow of fuel came out. After about 20 minutes it cranked fine. Got about a mile and it shut off again. Also, oil pressure was good. After about 45 minutes, it cranked. Got about another mile and shut off again. Then was pulled home. With a good flow of fuel coming out at the drain valve looks like fuel supply is not a problem. Unless the valve drains before the fuel passes through the filter and the filter is partially blocked. Said he thinks fuel filter should be ok since he changed it. Any ideas?