To reduce dispersion of an engine output effectively by detecting inner pressure of each cylinder per prescribed crank angle of a multiple cylinder engine, and judging whether a difference between net average effective pressure calculated per cylinder is larger than a predetermined value or not so as to judge dispersion of an engine output between cylinders.
A cylinder inner pressure sensor 11 for detecting inner pressure P in each cylinder as relative pressure to atmospheric pressure is disposed on an engine main body 7, and its output signal is inputted to an ECU 5 together with signals outputted from a cooling water temperature sensor 42, a throttle opening sensor 43, an intake temperature sensor 44, and a crank angle sensor 38. In the ECU 5, net average effective pressure is calculated according to a detected value of inner pressure per cylinder, and it is judged whether a difference between the net average effective pressure calculated per cylinder is larger than a predetermined value or not. When it is judged that the difference between the net average effective pressure per cylinder is larger than the predetermined value, control factors such as a fuel injection volume and an ignition timing are controlled so as to reduce the difference.
SHIMAZAKI YUICHI
ABE KENJI
KURODA YOSHITAKA
