Airflow Sensor
All intake air is drawn through the airflow sensor. The airflow sensor contains a tunnel with an airflow meter flap and dampening flap. The airflow meter flap swings with intake air stream against pressure of a spiral spring, and is connected to a potentiometer.
The potentiometer transmits an electrical signal determined by airflow meter flap position to inform ECU of engine load. At idle, the airflow meter flap is almost closed due to spring pressure. See Fig 1 .
The potentiometer within the airflow sensor prevents loss of engine power during engine load or sudden acceleration (along with engine speed and coolant temperature) by signaling the ECU of necessary enrichment and timing requirements.
The airflow sensor contains an intake air temperature sensor. An adjustable idle air by-pass screw influences CO levels at low engine speeds. A tamper-proof plug is installed over this screw.