GM Firebird 1967-1981 Repair Guide

Air Injection Reactor System (AIR)

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See Figures 1 through 8

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Fig. Fig. 1: Exploded view of the Air Injection Reactor (AIR) system used on 1967 6-cylinder engines



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Fig. Fig. 2: Exploded view of the AIR system used on 1967 8-cylinder engines



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Fig. Fig. 3: Exploded view of the AIR system used on 1968-74 6-cylinder engines



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Fig. Fig. 4: Exploded view of the AIR system used on 1968-74 8-cylinder engines



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Fig. Fig. 5: Exploded view of the AIR system used on 1975-76 inline 6-cylinder engines



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Fig. Fig. 6: Exploded view of the AIR system used on 1975-81 8-cylinder engines



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Fig. Fig. 7: Exploded view of the AIR system used on 231 V6 engines



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Fig. Fig. 8: Cross-sectional view of a common diverter (bypass) valve used on the AIR system

This procedure applies only to 1967-80 models. 1981 models are equipped with the Air Management System.

This system was first introduced on California cars in 1967. The AIR system injects compressed air into 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; those 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 the pump 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 AIR system on the 231 V6 engine is slightly different, but its purpose remains the same.

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 tightness of connections. Check the drive belt for wear and tension every 12 months or 12,000 miles.

COMPONENT REMOVAL Air Pump



See Figures 9, 10 and 11

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Fig. Fig. 9: Exploded view of the AIR pump mounting 1967-69 OHC 6-cylinder engines without power steering



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Fig. Fig. 10: Exploded view of the AIR pump mounting 1967-69 OHC 6-cylinder engines with power steering



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Fig. Fig. 11: Exploded view of the AIR pump mounting 1968-74 8-cylinder engines


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, then remove the pump.
  8.  
  9. Install the pump using the reverse of 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.  

Installation is performed in the reverse order of removal. Always use a new gasket. Tighten the valve securing bolts to 85 inch lbs.

 
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