Very Bizzar Problem...

if the pistons are moving and the valves are opening it should start on either ........ weird
i hope its somthing simple for you!

 

Won't start without diesel or if its been airlocked. I've heard of guys with bad take pickups lose fuel pressure on grades and loads due to it. I've also heard of tanks getting so full of water no fuel can make it through.

 

Sorry typo. I simply meant pickup... Some people cal it the siphon or draw line. Just check the tube in the tank is below the fuel otherwise you suck air. If its bent, too short, or busted you can get funky behavior, especially on grades.