Gran Fury V8-318 5.2L VIN P 2-bbl (1983)
Air Injection Control Valve: Description and Operation
Air Switching Valve (Combination Switch/Relief Valve)
1982-83 Rear Wheel Drive Models with EFI
The air switching system, is used on 1982-83 vehicles with Electronic Fuel Injection. Its purpose is basically the same as that for other vehicles with
an air switching valve. However, the controls and operation are slightly different.
The vacuum-actuated air switching valve used in this system, directs air from the air pump to either the "upstream" or "downstream" air injection
nozzles. A vacuum signal causes air to be directed upstream from the air switch valve. When there is no vacuum, the air is directed downstream. The
shuttle-type vacuum solenoid valve, when energized, allows engine vacuum to reach the air switching valve causing upstream air injection. When
de-energized, the solenoid valve blocks the vacuum signal to the air switching valve, causing it to switch to downstream air injection.
The vacuum solenoid valve is controlled by the ignition by the ignition key, a 70 second-delay time and the presence or absence of a cold enrichment
signal from the EFI electronics. When the engine is started, the vacuum solenoid valve is energized, causing upstream air injection. After starting, the
solenoid remains energized until the circuit is interrupted by the conclusion of the 70 second delay from the timer. At this point, downstream air
injection starts. If the engine is cold when started, the cold enrichment signal from the EFI must first end before the 70 second time delay can begin. If
the engine is hot, there will be no cold enrichment signal and downstream air injection occurs after 70 seconds.
