Concord L6-258 4.2L VIN C 2-bbl (1982)
Pulsair Valve: Description and Operation
Fig 47 Pulse Air Injection Reactor (PAIR) System
This system uses a series of pipes and check valves in the pulse air valve to route fresh air into the exhaust manifold, Fig. 47.
Engine operation causes a pulsating flow of exhaust gases which are of positive or negative pressure depending on whether the exhaust valve is
seated or not. If pressure is positive, the disc is forced to the closed position, allowing no air flow into the exhaust system. If pressure is negative,
the disc will open allowing fresh air flow into the exhaust system. Due to the inertia at high engine rpm, the disc fails to follow pressure pulsations.
Therefore, the disc will remain closed preventing air flow into the exhaust system.
Throttle closure during deceleration, momentarily causes air fuel mixtures too rich to burn. These mixtures, when combined with air, will become
combustible causing after fire.