CJ-7 L6-258 4.2L VIN C 2-bbl (1982)
Pressure Feedback Exhaust Sensor: Testing and Inspection
1. Start engine and allow to reach normal operating temperature.
2. Disconnect vacuum signal dump valve vacuum hose from manifold and plug the manifold connection.
3. Accelerate engine to 2,000 rpm. There should be vacuum at exhaust ports on bottom of valve. If not, replace valve.
4. Connect vacuum signal dump valve vacuum hose to manifold and accelerate engine to 2,000 rpm. There should be no vacuum at exhaust ports on
bottom of valve. If there is, replace valve.