COMPRESSION PRESSURE DETECTING METHOD FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To diagnose the abnormality of an engine by detecting the variation of the compressing pressure of an internal combustion engine from the variation of the load current when cranking the starter motor for the engine thereby detecting the compressing pressure without fixing a pressure sensor. CONSTITUTION:The load current variation when cranking a starter motor for an internal combustion engine is measured. The compressing pressure is detected from the ratio P/Po where Po is the peak load current during one cycle of the engine 1 or the peak amplitude of the load current under the normal state of engine while P is the peak amplitude of the load current under the abnormal state. In such a manner the abnormality of the compressing pressure can be detected easily thereby the breaking of a piston ring, incorrect head gap of the supply/exhaust valve and the break-down of the piston and the cylinder head can be detected.