Engine Controls - System/component Tests: Diagnosis Mazda MX-6 I

System Inspection

Purge system operation takes place when vehicle is accelerating in gear (off idle), engine is at operating temperature and oxygen sensor is functioning normally. (Scheme 76)

Scheme 76

1. Warm engine to normal operating temperature, and operate it at idle. Disconnect Positive Crankcase Ventilation (PCV) valve, together with vent hose, from valve cover. Block PCV valve opening and check for vacuum. If no vacuum is felt, check for collapsed line and blockage.
2. Note direction of valve installation. Remove PCV valve. Blow air into upper port of valve. Air should flow through valve from lower port. Blow air through lower port of valve. Air should not flow from upper port. Replace valve as necessary.

See also:
• PIN VOLTAGE CHARTS