Acceleration/Deceleration detection device and method for four-cycle engines

The engine acceleration detection device compares a intake manifold pressure at a certain crankshaft angle with the intake manifold pressure at 720 degrees before this crankshaft angle. If the difference between these two pressures is a predetermined value or more and the former is higher than the latter, the engine acceleration detection device determines that the engine is in acceleration status. The acceleration of the engine is determined without using a throttle valve opening sensor.