METHOD FOR MEASURING ATMOSPHERIC PRESSURE IN INTERNAL- COMBUSTION ENGINE

摘要

PURPOSE:To enable engine control meeting the pressure of an intake pipe during measurement of the atmospheric pressure with simple constitution by calculating the magnitude of the atmospheric pressure on the basis of the magnitude of the downflow pressure in a throttle valve when the engine speed is a prescribed number of revolution or above and when the opening degree of the throttle valve in the engine intake line is a prescribed opening degree or above. CONSTITUTION:The information on the opening degree of a throttle valve, intake pressure, temp. of cooling water and concn. of oxygen is supplied alternatively from an A/D converter 23 to a CPU30. The information on engine speed is supplied via a bus line 33 to the CPU30 from a counter 25 and the information on the on-off of an ignition switch 17 and a starter switch 18 is supplied thereto from a module 27. The CPU30 reads out various sets of information according to the operation program stored preliminarily in an ROM31 and calculates the fuel injection time corresponding to a fuel feed rate from the prescribed equations at every prescribed revolution of an engine 4 or at every sampling timing determined by a prescribed clock pulse. A driving circuit 28 drives an injector 15 for as much as the calculated fuel injection time to feed fuel to the engine 4.