Abnormality detecting device for an automobile engine

Claim 1

An abnormality detecting device for an automobile engine which comprises: an airflow sensor for detecting a load to an engine, a revolution speed sensor for generating pulses in response to a revolution speed of the engine, an oxygen sensor for detecting the components of exhaust gas from the engine, injectors for injecting fuel to an air intake pipe, and a controlling device which measures a period of the pulses of the revolution speed sensor to thereby judge the presence or absence of misfiring based on a value indicating a change of angular speed or the like, and/or judges abnormality in a fuel supply system which is caused by abnormality in the airflow sensor and the injectors, and which nullifies an alarm to be generated on the basis of the judgment of abnormality in a case that the temperature of the fuel is determined to be higher than a predetermined value from an information of fuel temperature obtained by a temperature sensor after the engine has been re-started while the engine has been in an elevated temperature state after the stopping of the engine, or in a case that a predetermined time set by a timer has not been past after the re-starting of the engine.