Digital Ignition Timing: Diagnosis

The following should be considered when diagnosing the system:

• With a closed throttle and an intake air temperature below 120-140°F (50-60°C), ignition timing will only be changed by engine speed.
• If wire connection on left wheel housing in engine compartment is disconnected, ignition timing is retarded by 7°. Plug can be disconnected to eliminate detonation in areas where poor quality gasoline is provided.
• If temperature sensor fails or wire is pulled off, ignition timing will be retarded.
• If pressure sensor of control unit fails or pressure hose is disconnected or leaks, ignition timing will be advanced. Be sure connections are tight and pressure hoses are correctly routed.
• If throttle switch fails or a wire is pulled off, there will be no ignition retard during starting or coasting, and idle speed will be too high.
• If flywheel sensor fails, entire system will not operate.