I am actually a diesel/generator mechanic but this engine fuel system is a lot different then my stuff. I started at the basics and replaced every poly/soft line on the truck and new fittings last night then drove home I will start in a little bit and see if it leaks or is hard start. Anybody have a diagram on the motor or fuel system layout and components I am not sure about how some of the componets factor in. Also where is the fuse for the pump I didnt check that.
The plastic lines are the fuel return lines, and are low pressure. Any leak in them will just drool. The steel lines that go between the injector pump and the injectors are very high pressure. When they leak, you will get a fine spray. Usual place for them to leak is at the fitting nut. The steel line can break there as well.
There really is no significant difference between the MF injection system and any other direct injection pump system. The differences are in details that are not readily visible... such as: the fuel density compensator, injectors that don't atomize fuel, but rather squirt, the deep combustion chamber built into the piston top, and the 22.5:1 compression ratio.
The fuse for the tank fuel pump is under a small box that is on top of the fuel pump. It is the box where the wires go to on the tank.
-Chuck