Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Pulsed Secondary Air Injection: Testing and Inspection
1.
If a pulse air valve emits a hissing noise, the valve may be defective or improperly torqued. Inspect valve and make necessary repairs.
2.
If one or more valves fail, exhaust gas will enter the carburetor through the air cleaner, resulting in poor driveability. Inspect valves and ensure that
pulse air pipe extension tubes are installed in exhaust manifold.
3.
Exhaust gases passing through the pulse air valve will transmit excessive heat to rocker cover plenum, indicated by burned off paint. This
condition will also cause the deterioration of rubber grommets and hoses. Repair or replace parts as necessary.
4.
If hose leading to air cleaner deteriorates, particles may enter carburetor and cause poor driveability. Clean carburetor and remove particles from
pulse air plenums and connecting pipe.
5.
To test air valves for proper operation, connect adapter tool J-23738 with a length of 3/4 inch hose to grommet end of valve to create a vacuum.
Apply 15 inches Hg to valve. If vacuum drops to 6 inches Hg in less than two seconds, replace valve.
Refer to ``Catalytic Converters'' for ``Exhaust System Restriction Check.''
