It has nothing to do with charging system.

Since the battery voltage is 12.3 V (though a little bit lower than normal 12.6 V) and you could hear engine cranking, it has nothing to do with starter and battery, nor charging system. Check if you have any spark plug problem (see my earlier entry in your previous entry), if not, check fuel pump fuse, fuel filter, fuel line and fuel pump. If fuse and fuel filter is ok, most likely it is the fuel pump failure. Fuel pump usually has a life of at least 100 k miles.