METHOD AND APPARATUS FOR DIAGNOSING ENGINE FAULT

According to a method and an apparatus (14) of the present invention for diagnosing a fault of an engine (16), a cranking rotation state is created by rotating a crank shaft (24) while explosions in each cylinder (22) are stopped; a variation (Ӄ) of angular velocity of the crank shaft (24) is detected for each cylinder (22) in the cranking rotation state; a cylinder the compression pressure of which is insufficient is detected based on the variation (Ӄ); and if a cylinder indicated as a misfiring cylinder by a fault code is the same as the cylinder detected as being insufficient in compression pressure in the cranking rotation state, the cylinder is specified.