See Figures 1 and 2
The air/fuel mixture solenoid provides a method of controlling the amount of fuel supplied to the engine, throughout all engine operating conditions. By monitoring the inputs from various sensors, the ECM can vary the ON or OFF time of the solenoid; this in known as the duty cycle. By continually adjusting the duty cycle every 65 milli-seconds, the optimum air/fuel mixture, for all engine conditions, can be provided.
- Turn off ignition and disconnect air/fuel ratio solenoid harness connector.
- Measure the resistance of the solenoid. The resistance should be 30-50 ohms. If air/fuel solenoid resistance is out of specification, replace solenoid assembly.
- If solenoids are within specifications, reconnect solenoid harness connectors.
- Disconnect ECM 10 pin connector from control unit and disconnect alternator L terminal.
Turn ignition switch ON and measure voltage between terminal
If battery voltage is not present, check and (if necessary) repair/replace harness.
REMOVAL & INSTALLATION
See Figures 3 and 4
- Drain approximately one quart of engine coolant.
- Remove carburetor from engine.
- Disconnect harness from harness connector and cut the harness cover at the connector.
- Remove choke chamber assembly from carburetor.
- Remove air/fuel ratio solenoid from choke chamber.
- Use new O-rings on solenoid and apply a light coating of oil to O-rings.
- Install solenoid and torque mounting bolts to 12-36 inch lbs. (1.5-4 Nm).
- Install choke chamber assembly.
- Install new boots and terminal ends to harness with terminal pliers, and then place terminals in connector.