What fuel system is the truck....LPG? Gasoline?? diesel?? How many hours are on the truck?
If it is a LP truck check the tank fitting to make sure it is tight,and tank is oriented in the correct position. Does the truck fire back up again after it shuts off? It sounds like a fuel issue to me,a code would be present for most everything else,did someone just change the LP tank and it started acting this way,I have seen where at a tank change the flat gasket in the tank couple gets caught on the Female connector and then you try and screw it onto a new tank and now you have two gaskets in it and it Doesn't screw down tight enough...just something to check...also on top of the NIKKI regulator is a 17 mm hex take it out and put a PSI gauge in it and see what your fuel pressure is!should be about 4.5 PSI.........