Caprice V8-265 4.3L VIN W MFI (1995)
Air Injection Pump: Testing and Inspection
The Air Injection Reaction (AIR) pump is a regenerative turbine type which is permanently lubricated and requires no periodic maintenance.
The engine should be at normal operating temperature in neutral at idle. Using the scan tool select "Miscellaneous Test" then "Output Test." Select "AIR
System" in "Output Test" directory. Select Heated Oxygen Sensor (HO2S) voltages for both Bank 1 and Bank 2 HO2S.
Enable the "Output Test" for the AIR system. The "Output Test" will energize the AIR pump for only 5 seconds. When the output Test" is enabled, the
HO2S voltages for both sensors should remain under 300 mV because air is being directed to the exhaust ports. If the HO2S voltages remain low during
the "Output Test," the AIR pump and integral stop valve are operating satisfactorily.
If the HO2S voltage does not remain low when the "Output Test" is commanded "ON," proceed as follows.
1. For a seized AIR pump.
2. Hoses, tubes and all connections for leaks and proper routing.
3. For air flow going to the exhaust ports.
4. AIR pump for proper mounting.
