Method and system for diagnosing common rail diesel engine

摘要

Disclosed are a method and a system for diagnosing a common rail diesel engine. The method for diagnosing a common rail diesel engine may include setting a time when a pressure of a common rail becomes a first set pressure to a diagnosis start time and neglecting a state of the common rail until the pressure of the common rail decreases from the first set pressure to a second set pressure which is a diagnosis end pressure, verifying a time when the pressure of the common rail becomes the second set pressure and determining the time as a diagnosis end time when the pressure of the common rail becomes the second set pressure, calculating a diagnosis time as an elapsed time from the diagnosis start time to the diagnose end time, and diagnosing that fuel leaks from the common rail when the diagnosis time is shorter than a diagnosis set time by comparing the diagnosis time with the diagnosis set time.