FIELD: engines and pumps.
SUBSTANCE: internal combustion engine (50) comprises a valve adjusting mechanism (60) having a plurality of cams used to drive the exhaust valve (55) and an electronic control unit (70). The electronic control unit (70) is able to select from among a plurality of cams of the operating cam, which is a cam used to drive the exhaust valve (55). The electronic control unit (70) determines whether there is an abnormality in the switching of the operating cam based on the rate of change of pressure in the cylinder (51a) over a predetermined period. The predetermined period is the period during which the discharge valve (55) is opened.
EFFECT: possibility of detecting the presence of an abnormality in the switching of the working cam, which can cope with situations when the switching of the working cam occurs abnormally.
18 cl, 78 dwg
