I have a 1996 3/4 ton 2 wheel drive 6.5 turbo. I have 205,000 miles and replaced my FSD about 6,000 miles ago. The truck won't start. I replaced my lift pump, fuel filter and have swapped in / out various FSD's and the truck still won't start. My glow plugs are working. It seems like the truck initially gets fuel when I activate the starter because it fires up for about a second then dies. My batteries and connections seem to be OK as well.

Any suggestions out there? Bad electrical connections? Or dead ECM?