Air Injection: Testing and Inspection

Air Management System:

Air Management Valve:

AIR MANAGEMENT SYSTEM TESTING

1. Warm up engine to normal operating temperature.
2. Disconnect hose to air cleaner, start engine and run at idle. If system is operating properly, air should flow to the exhaust ports for the first 5 seconds and then switch to the air cleaner. Check manifold vacuum at air management valve (AMV) with engine at idle. It should be 10 inHg. Repair if necessary.



AIR INJECTION PUMP INSPECTION

Raise engine speed to approximately 1500 rpm and check air flow from hose. If flow increases with engine speed, pump is operating satisfactorily. If not, check for:
1. Proper drive belt tension.
2. Leaking pressure relief valve. Air may be heard leaking with pump running.

The air pump is not completely noiseless. Under normal conditions, noise rises in pitch as engine speed increases. To determine if excessive noise is emanating from the air pump, momentarily operate the engine with pump belt removed. Check for:
1. Seized air pump.
2. Proper pump mounting and bolt torque.
3. Proper hose routing and connections.

The air pump is permanently lubricated and requires no periodic maintenance.

CHECK VALVE TESTING

1. The check valve would be inspected whenever the hose is disconnected or whenever failure is suspected. A pump that had become inoperative and shown evidence of exhaust gas entry would indicate check valve failure.
2. Remove check valve. Air should pass freely when the valve is blown through from air pump side. No air should pass when the valve is blown through from the exhaust manifold side.
3. Replace a valve which does not operate properly.

AIR HOSE AND INJECTION PIPE INSPECTION

Check:
1. Hoses and pipes for holes or deterioration.
2. Hose and pipe connections and clamps for tightness.
3. Hose and pipe routing. Interference with other components may cause wear.
4. If a leak is suspected on the pressure side of the system or if a hose or pipe has been disconnected, the connections should be checked for leaks with a soapy water solution. With the pump running, bubbles will form if a leak exists.