900 L4-1985cc 2.0L DOHC (1986)
1. Remove the plug from the potentiometer screw on the side of the mass air flow sensor.
2. Unplug the wiring harness connector from the mass air flow sensor.
3. Connect the multimeter to pins 3 and 6 as shown in the figure. The instrument should read 380 ohms. Adjust as necessary by turning the
potentiometer screw. This is the first step in checking and adjusting the basic setting.
4. Plug the wiring harness into the mass air flow sensor again.
5. Connect pulse ratio meter 83 93 597 to the test point adjacent to the evaporator housing by means of the adapter lead in 83 94 132.
6. Start the engine and run it until the radiator fan cuts in.
7. If the basic setting is correct, the meter needle will swing back and forth between both ends of the scale.
Note: The movement of the needle will not be rapid and there may be a pause between each movement.
8. If adjustment is necessary, turn the potentiometer screw in the mass air flow sensor as follows:
A. If the needle remains stationary at the higher end of the scale or spends most of its time at this end, turn the screw anticlockwise until the
needle stays roughly the same length of time at both ends of the scale.
B. If the needle remains stationary on the lefthand side of the scale, turn the potentiometer screw until it stays roughly the same length of time at
both ends of the scale.
9. Fit the plug back in the mass air flow sensor.
