Fail-safe method and apparatus for internal combustion engines

摘要

In an engine control system which determines the amount of fuel to be injected on the basis of an intake pipe pressure detected downstream of a throttle valve and engine speed (D-EFI), fail-safe action is provided when a failure of an intake pipe on the downstream side of the throttle valve is detected. The fail-safe apparatus of the present invention is designed to signal the occurrence of an abnormality with the intake system when the throttle valve is not being opened, that is, the throttle valve is stationary or is closing, a vehicle speed variation exceeds its specific value and the engine speed exceeds its specific value. When these conditions are detected, engine power is controlled lower, thereby assuring vehicle driving safety.