| 摘要 |
PURPOSE:To make it possible to change over fuel pressure with the use of a simple and cheap means, by selectively introducing pressure upstream or downstream of a throttle valve into a pressure regulating device in accordance with the load of the engine. CONSTITUTION:The pressure P0 upstream of a throttle valve 6 becomes positive upon super-charging operation by the atmospheric pressure or a turbo-supercharger 14, but the downstream pressure P1 is negative. An I/O device 41 receives a rotational speed signal (IS1), an intake-air pressure signal (IS2), a throttle valve opening degree signal (IS3), a water temperature signal (IS4) and an intake-air temperature signal (IS5). When the engine operates under a load condition such as, for example, idling condition, the I/O device 41 issues a drive signal from its output port OS1 to change over a three-way solenoid valve 1 from the present condition (standard condition) in which the upstream pressure P0 is taken into a regulator 2, to the next condition (low pressure condition) in which the downstream pressure P1 is taken into the regulator 2. The necessary compensation necessary for calculating the pulse width of drive pulses fed to an injector 3 through the output port OS2 is carried out in accordance with a program stored in an ROM44. |
