Air Injection: Testing and Inspection

AIR MANIFOLD, HOSE & TUBE

1. Inspect all hoses for deterioration or holes.
2. Inspect all tubes for cracks or holes.
3. Check all tube and hose routing as interference may cause wear.
4. Check all hose and tube connections.
5. If a leak is suspected on the pressure side of the system, or any tubes and/or hoses have been disconnected on the pressure side, the connections should be checked for leaks with a soapy water solution. With the pump running, bubbles will form if a leak exists.
6. To replace any hose or tube, note the routing, then remove the hose(s) or tube(s) as required. The hoses used with this system are made of special material to withstand high temperature. No other type hose should be substituted.

CHECK VALVES

1. Check valves should be inspected whenever the hose is disconnected from the check valve or whenever check valve failure is suspected. An air pump that has shown any indications of having exhaust gases in the pump would indicate check valve failure.
2. Disconnect air supply hose from injection manifold, and listen and feel for exhaust leakage from check valve with engine running above idle. Slight leakage is normal.




V6-173 ENGINES EXC. CALIF.

1. Bring engine to normal operating temperature, then remove air cleaner cover.
2. Disconnect diverter valve lower vacuum hose and check for air being directed to air cleaner.
3. Reconnect diverter lower vacuum hose and check for air being redirected to exhaust manifolds. If air is not diverted when vacuum hose is disconnected, check vacuum source for vacuum. If vacuum is present at source, replace diverter.



V6-173 ENGINES CALIFORNIA
This type of diverter valve is a combination electrical and vacuum switching valve and is controlled directly by the electronic control module so that air is diverted to the air cleaner five seconds after engine start, under high engine loads and during closed throttle deceleration. Voltage should not be present at diverter valve with ignition in ``Off'' position.




AIR INJECTION TUBE
There is no periodic service or inspection for air injection tubes. However, whenever the cylinder head is removed from In Line engines, or whenever exhaust manifolds are removed from V6 and V8 engines, inspect the tubes for carbon buildup and warped or burnt tubes. Remove any carbon buildup with a wire brush. Warped or burnt tubes must be replaced.

AIR INJECTION PUMP

1. Accelerate engine to about 1500 rpm and observe air flow from hose or hoses. If air flow increases as engine is accelerated, the pump is operating satisfactorily. If air flow does not increase or is not present, proceed as follows:
2. Check for proper drive belt tension.
3. Check for leaky pressure relief valve. Air may be heard leaking with the pump running. The air pump system is not completely noiseless. Under normal conditions noise rises in pitch as engine speed increases. To determine if excessive noise is the fault of the system, operate the engine with the pump drive belt removed. If excessive noise does not exist with the belt removed, proceed as follows:
a. Check for seized air pump.
b. Check hoses, tubes, air manifolds and all connections for leaks and proper routing.
c. Check carburetor air cleaner for proper installation.
d. Check air pump for proper mounting.
e. If none of the above conditions exist and the air pump has excessive noise, remove and replace the pump unit.