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Home >> Mercury >> 1994 >> Villager LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Emission Systems & Sub-Systems >> Secondary Air Injection >> Air Injection By-Pass Valve (Normally Open)

Air Injection By-Pass Valve (Normally Open)

  1. Disconnect air supply hose at inlet. Accelerate engine to 1500 RPM and verify presence of airflow in hose. Reconnect air supply hose to valve inlet.
  2. Carefully disconnect air supply hoses at outlets "A" and "B". See Fig 1 . Carefully remove vacuum line at vacuum nipple. Accelerate engine to 1500 RPM. Airflow should be heard and felt at outlet "B" with little or no airflow at outlet "A".
  3. Connect a vacuum line from manifold vacuum fitting to air control valve vacuum nipple. Accelerate engine to 1500 RPM. Airflow should be heard and felt at outlet "A" with little or no airflow at outlet "B".
  4. If conditions in steps 2) and 3) are not as specified, replace air control valve. If valve operates satisfactorily, restore all hose and vacuum connections.
Fig 1: Testing Normally Open Air By-Pass Valve
G90I14330Courtesy of FORD MOTOR CO.
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