GM 7836179 PUMP

AIR system used in models from 1975 to 1980 pumps compressed air into the exhaust system around the exhaust valves so as to help in burning the unburned exhaust gases; it comprises of air injection pump/hoses/valves/tubes directing the air to the exhaust manifolds. Adjustments as applied to carburetors and distributors are uniquely different for AIR engines and these components are not interchangeable with typical engines. A alternates between closing off the air entering the engine to stop backfiring when manifold vacuum rises and uses a diverter value at cruising to channel air through the pump muffler and expels it by a relief valve at high rpms. Check valves are used in the system to prevent exhaust gases from entering the pump, and the AIR system used in the 231 V6 engines has some differences in this aspect. The efficiency of the system depends on the idle speed, ignition timing and dwell, which must be checked from time to time and the hoses and fitting must be checked for wear and tightness and the drive belt for wear and tension every one year or every 12,000miles. As for access to the air pump: disconnect the air hoses, secure the pump pulley, loosen the mounting bracket bolt, remove the drive belt, unbolt the pump mounting bolts and then remove the pump; installation is the reverse of removal. Subsequently, for the diverter valve, the vacuum sensing line and other hoses need to be disconnected, and then the valve is unbolted from the connection, the original gasket must be replaced with a new one and then nuts and bolts must be tightened to around 85 INCH LBS.