400 L4-156 2.6L (1982)
Fig. 18a Coasting Air Valve System
PURPOSE
These deceleration devices decrease HC emissions during vehicle deceleration. The system consists of an Air Switching Valve (ASV), Coasting
Air Valve (CAV) and a Deceleration Spark Advance System (DSAS).
OPERATION
During vehicle deceleration;
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The ASV--activated by carburetor ported vacuum--cuts off fuel flow to the by-pass holes and pilot outlet by supplying additional air through
the low speed passage to reduce HC emissions.
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The CAV--also activated by carburetor ported vacuum--supplies additional air into the intake manifold.
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The DSAS advances ignition timing, which is usually controlled by carburetor ported vacuum and engine speed.
When the engine speed sensor detects engine speed below 1,300 rpm ASV & CAV operation is interrupted by opening the solenoid valve, to
maintain smooth vehicle operation and eliminate engine stall.
