| 摘要 |
PURPOSE:To maintain a control function for an air-fuel ratio by using a heat ray current meter as an intake air detector to control the air-fuel ratio precisely and using an intake negative pressure detector when the heat ray current meter is in trouble. CONSTITUTION:An output signal from a heat ray current meter 1 or an intake negative pressure detector 2 is input to a signal processing circuit 7 optionally by a switch 6. When the output level of the heat ray current meter 1 indicates an abnormal value, the output of the intake negative pressure detector 2 is input to the signal processing circuit 7. The signal processing circuit 7 controls an optimum opening time of a fuel injection valve 9 by processing engine parameters too. Thus, a control function for an air-fuel ratio can be maintained even when the heat ray current meter is in trouble. |
