3406 going through check valves

Something is coming apart from the inside out. I can remember if the check valve is before or after the filter. You could have a fuel line that is flaking off material from the inside and getting stuck in the check valve or something from the filter.

 

Need to hook it up to a laptop with CAT ET. The fuel valve will NOT bring on a check engine light when it fails. The only thing the ECM reads in the fuel system is temperature.

Whatever is bringing on the check engine light is the cause of the problem. You can get a flash fault code from the ECM by turning the key to the on position and then holding the Set/Resume switch for the cruise control to the set position for 3 seconds, when you release it the check engine light will flash. Count the flashes, if it flashes 5 times pauses and then flashes 5 more times that's a code 55........this means nothing is wrong at that moment.

 

Timing sensor...............this will cause hard starting along with other symptoms.

I'm going to assume this is a 2WS serial number engine, because of the year of the truck...........you have two timing sensors.