Method and system for a common rail fuel system

Abstract

In one embodiment, a common rail fuel system for an engine of a vehicle, such as a locomotive, comprises a higher-pressure fuel sub-system and a lower-pressure fuel sub-system, wherein a pressure limiting valve, is in fluid communication with to the higher-pressure fuel sub-system to relieve excess pressure. In a condition where pressure of the higher-pressure fuel sub-system is below a desired and expected threshold, it is possible that the pressure limiting valve is open. An example method is provided to close the pressure limiting valve and determine if opening of the pressure limiting valve is the cause of the pressure being below the threshold or if a leak is present in the common rail fuel system. In this manner, unnecessary disabling of the engine is avoided and, if a leak is present, the leaking sub-system is identified.