California Vehicles (Digifant I)

Fig. 15 Air flow meter:

Intake air flow volume is measured by the air flow sensor. It is located in the intake passage between the air filter and the intake manifold, and provides information concerning the rate of air flowing into the engine for the Digifant I control unit. This input, along with RPM, is used to calculate basic injector pulse width.

Air Flow Meter/Air Intake Sensor:

A measuring flap which is connected to a potentiometer swings in the airstream against the pressure of a spring. The potentiometer within the air flow sensor is provided with a constant reference voltage from the Digifant I control unit. As air is drawn into the engine, the movement of the measuring flap causes the wiper contact of the potentiometer to move. This movement modifies the reference voltage, which is recognized by the Digifant I control unit as a measure of incoming air.
Incorporated into the air flow sensor is the air temperature sensor. This sensor provides the Digifant I control unit with information concerning the ambient temperature of the incoming air. Since cooler air is more dense than warm air, this information is necessary as a correction value for calculating air intake volume.

NOTE: Because of its adaptive capability, the Digifant I control unit MUST be returned to its reference settings IF:

1. The coolant temperature sensor (blue connector) has been disconnected while the engine is running.

2. Any of these components have been replaced:
^ Digifant I control unit
^ Air flow sensor
^ Throttle valve potentiometer
^ Throttle body

Refer to RESETTING DIGIFANT I CONTROL UNIT.