Upon examination, the tank and the inlet filter to the fuel pump appear to be clogged with rust. The clogged inlet filter was most likely being collapsed over the inlet and restricting the fuel flow. The attached image shows the inlet filter cut apart with and trapped rust.
Toward the middle of the trip, it became apparent that shutting off the engine and restarting would dramatically reduce fuel starvation. Unfortunately, this fix only lasted for about 100 miles. We repeated this over and over, even shutting down the engine while coasting down hills.
We began to think about a collapsed inlet fuel filter. This filter is supposed to catch gross contamination and water. Fine contamination is meant to be caught by the in-line filter. If there is a gross amount of rust or other trash in the tank, it may actually clog this small inlet filter. So, we limped back to Alabama while crossing our fingers that the fuel pump would not fail, shutting down the engine and restarting when it starved. We added 2 cycle oil in the fuel to provide extra lubrication for the pump. I think we were lucky to get home without a major breakdown.
The solution chosen here is to replace the fuel tank with a new one and the fuel pump with a new assembly. The cost of the parts at AutoZone is 400 bucks. A repair like this at a Ford dealer would cost well in excess of a grand and it would have delayed us for about a week as the new fuel tank was shipped in. That makes this $4,500 truck not look so good. Nevertheless, this is what happens with trucks. No use worrying about it, just cough up the money and mark it down to another camping experience.
As second posting below shows the old fuel pump assemble and the new one. Perhaps this is instructive to some and I will report later if this actually fixes the problem. _John D
