Chevrolet 7842076 Pump Assembly, Air Injector

The Air Management System (AMS) introduces extra oxygen after exhaust gasses through the combustion chamber are ejected and works similarly to the AIR system. Located upstream the exhaust port is an engine-driven air pump sending air into the exhaust ports or manifolds or catalyst; the air pump works always, temporarily by-passing air through the Air Management Valve during deceleration and high speed; there is a check valve preventing back flow of exhaust. This system cuts HC and CO emission by opening the exhaust ports to the air intake during cold engine operation and help the catalytic converter to heat up quickly. During the warm up the air is supplied to the beds of the catalytic converter in order to reduce the level of HC and CO and, at the same time, the oxygen level remains low in the first bed for accurate reduction of NOx. The ECM controls air intake to include air to the air cleaner or atmosphere depending on the engine temperature and operating condition to avoid back firing during deceleration. Normal inspections of the check valves and hoses to look for formation of leaks, cracks or deterioration must be made. For removal and installation of the air pump, one has to loosen the V-belt adjuster bolt-The belt has to be removed-Unscrews the mounting bolts, and for installation, do the reverse while ensuring the belt tension is correct. The check valve consists of removing the check valve line from the pump assembly then removing the check valve from the air injection pipe, the reverse of how it is fitted. For the Air management valve, one has to disconnect the negative cable, take off the air cleaner, tag and disconnect the hoses and air management valve bolts and reassemble the air management valve in the reverse procedure.

Components of this system on GM engines include the air injection pump, an air diverter valve, manifold and injection tubes, and check valves for each hose leading from the pump.