Carburetor Feedback Testing

Figure 3:

1. Using a Digital Volt Ohm Meter connect the positive lead to the Oxygen Sensor Checker terminal (Figure 3). Connect the negative lead to a good ground on the engine block.


2. Connect a tachometer to the engine.

3. Insert the exhaust analyzer probe into the tailpipe.

4. Start the engine and warm up the engine to normal operating temperature.

5. Idle the engine for 5 minutes. Check the maximum oxygen sensor voltage produced at idle and note reading.

NOTE: The Oxygen Sensor checker terminal has 2 electrical connectors. Connect the positive lead of the Digital Volt Ohm Meter to the connector with the shielded wire. If the voltmeter reads 0 Volts connect the positive lead to the other connector and recheck. If both readings are 0 volts then the Oxygen Sensor is inoperative and replacement is necessary. The oxygen sensor voltage will vary continuously. Use only the highest voltage produced when checking.

6. Run engine at 2500 RPM.

7. Check CO at tail pipe and note reading at 2500 RPM.



8. Refer to the flowchart for necessary repair procedures.

9. Proceed to Carburetor removal.