Air Flow Meter/Sensor: Adjustments

SENSOR PLATE HEIGHT
- Run the fuel pump for a few seconds to build up system pressure
- Remove rubber connecting boot from the air sensor housing
- Check position of sensor plate
Upper edge of sensor plate must be 1.9 + 0.2 mm below the cone edge of the air venturi on the side closest to the fuel distributor

TO ADJUST:
- Lift sensor plate fully
- Adjust position of sensor plate by bending wire clip
Be careful not to scratch the venturi of the air flow sensor
Do not bend the leaf spring

SENSOR PLATE CLEARANCE
- Lift sensor plate until even resistance is felt Minimum noticeable clearance
Maximum 1.9 + 0.2 mm (sensor plate even with edge of cone)
- If OK, continue with sensor plate/control plunger movement checks
- If not OK, perform sensor plate lever basic adjustment





SENSOR PLATE/CONTROL PLUNGER MOVEMENT
Both the air sensor plate and the control plunger must move freely to insure accurate control of the air fuel mixture. Clean any oil residue from the air sensor plate. (Oil residue can cause the plate to bind.)
- Energize fuel pump for 5 seconds to build up system pressure then turn pump off
- Using pliers or a magnet, lift sensor plate through entire range of lever and control plunger travel. An even resistance must be felt
- If the plate binds, check the centering of the sensor plate and sensor lever
- If OK, replace fuel distributor





SENSOR PLATE LEVER BASIC ADJUSTMENT
The following adjustment must be made whenever the air sensor housing or the fuel distributor is replaced.
- With fuel distributor removed check distance between seating pads of removed fuel distributor on the air flow sensor and the roller on the sensor plate lever
Distance should be 19.0 +/- 0.1 mm (.748 +/- .004") on 4 cylinder engines.
Distance should be 21.0 +/- 0.1 mm (.827 +/- .004") on 5 cylinder engines.








SENSOR PLATE LEVER BASIC ADJUSTMENT (CONT'D)
- If measurement is incorrect, adjust CO%: adjusting screw to obtain correct specification
- Reinstall fuel distributor
- Recheck sensor plate clearance
- If OK, readjust idle speed and CO%
- If not OK, remove fuel distributor and adjust sensor plate clearance with stop screw of control plunger
Clockwise will increase clearance
Counterclockwise will decrease clearance
1/4 turn changes sensor plate position approximately 1.3 mm (.050")
- Reinstall fuel distributor and check sensor plate height:(Distance a 0.6 mm (0.024 in.) between stop screw and flange of hex nut)

NOTE: After adjustment, readjust idle speed and mA current (CO value) reading.

SENSOR LEVER/SENSOR PLATE CENTERING
The sensor plate must be centered in the air cone. The edges must not touch the sides of the air cone or free movement of the plate will be restricted





TO CENTER THE SENSOR PLATE
- Remove the 10 mm adjusting bolt from the center of the plate
- Coat the bolt with loctite
- Re-install the bolt (finger-tight)
- With centering tool US 1109 or a .10 mm (0.004") feeler gauge, carefully center the plate
- Torque the adjusting bolt to 5 - 7 Nm (4 ft/lbs.)
- If plate cannot be centered and lever appears to be off center in air cone, remove air sensor housing





TO CENTER THE SENSOR LEVER
- Remove clamping bolt on sensor lever counter-weight
- Coat the bolt with loctite
- Re-install the bolt (finger-fight)
- Slide lever to center position
- Tighten clamping bolt