Chevrolet Nova/ChevyII 1962-1979

Air Injection Reactor System

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OPERATION





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Fig. Fig. 1 Air Injection Reactor (AIR) schematic



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Fig. Fig. 2 Cross-sectional view of a diverter valve

This system was first introduced on California cars in 1966. The Air Injection Reactor (AIR) system injects compressed air into the exhaust system, close enough to the exhaust valves to continue the burning of the normally unburned segment of the exhaust gases. To do this, it employs an air injection pump and a system of hoses, valves, tubes, etc., necessary to carry the compressed air from the pump to the exhaust manifolds. Carburetors and distributors for AIR engines have specific modifications to adapt them to the air injection system; these components should not be interchanged with those intended for use on engines that do not have the system.

A diverter valve is used to prevent backfiring. The valve senses sudden increases in manifold vacuum and ceases the injection of air during fuel-rich periods. During coasting, this valve diverts the entire air flow through a muffler and during high engine speeds, expels it through a relief valve. Check valves in the system prevent exhaust gases from entering the pump.

The 1975 and later AIR system remains basically the same in some engine applications. However, some engines use a converter AIR system in which air is injected into the exhaust system ahead of the catalytic converter.

SERVICE



The AIR system's effectiveness depends on correct engine idle speed, ignition timing, and dwell. These settings should be strictly adhered to and checked frequently. All hoses and fittings should be inspected for condition and the tightness of connections. Check the drive belt for wear and tension every 12 months or 12,000 miles.

REMOVAL & INSTALLATION



Air Pump


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Fig. Fig. 3 Air pump and related component mounting-1972 6-cylinder engine shown



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Fig. Fig. 4 View of the air pump and related components-1972 vehicles



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Fig. Fig. 5 Air pump hose location and routing-1973 small block V8 engines shown



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Fig. Fig. 6 Air pump hose location and routing-1973 big block V8 engines shown


WARNING
Do not pry on the pump housing or clamp the pump in a vise; the housing is soft and may become distorted.

  1. Disconnect the air hoses at the pump.
  2.  
  3. Hold the pump pulley from turning and loosen the pulley bolts.
  4.  
  5. Loosen the pump mounting bolt and adjustment bracket bolt. Remove the drive belt.
  6.  
  7. Remove the mounting bolts, and then remove the pump.
  8.  
  9. Install the pump by reversing the removal procedure.
  10.  

Diverter (Anti-Afterburn) Valve
  1. Detach the vacuum sensing line from the valve.
  2.  
  3. Remove the other hose(s) from the valve.
  4.  
  5. Unfasten the diverter valve from the elbow or the pump body.
  6.  
  7. Installation is the reverse of removal. Always use a new gasket. Tighten the valve securing bolts to 85 inch lbs.
  8.  

 
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