Single Air Pump

Air Injection System Diagnosis:

DIAGNOSIS


CHECK VALVE

Remove air hose from check valve inlet tube. If exhaust gas comes out of the inlet tube, the valve has failed and must be replaced. If excessive noise is coming from the check valve or tube assembly, then the check valve and/or tube assembly need to be replaced.


AIR SWITCH RELIEF VALVE TEST

Apply 10 inches Hg vacuum to the air switch/relief valve. If air injection is not upstream, or if injection is both downstream and upstream, then the valve is defective. The relief valve portion of this assembly is defective if air escapes from the silencer at idle. If either of these previous conditions exist, the whole valve must be replaced.


AIR SWITCH/RELIEF VALVE SOLENOID

1. Disconnect electrical connector from solenoid valve.
2. Remove vacuum hoses. With the solenoid wire disconnected air should flow from the vacuum port through the vent port. Energize the solenoid, air should flow through both vacuum ports. If either test fails, the solenoid valve must be replaced.
3. Connect either solenoid terminal to a ground and the other one to the battery positive terminal. The solenoid should make a clicking noise when the connection to the battery is made.



DIVERTER VALVE (SOME MODELS)

If air escapes from the silencer at idle and makes excessive noise, then the diverter valve is defective.