had a cat guy come and run his diagnosis on it and he said all the fuel pressures are right and that's when he changed the main wire harness.. he did switch the vaporizer to no avail. did not check the compression as the truck ran well before this event but will check tomorrow. pretty sure it stops sparking. when you hook up a spark detector it mirrors the way that it fires then stops. Is there an auxiliary shutdown function on the ecu? could it be a mechanical malfunction in the timing system? I did take the rocker cover off and checked that the valves were opening and closing all the way. my cat guy seems to have given up so any thoughts would be great.