Gran Fury V8-318 5.2L VIN M 4-bbl (1982)
Vacuum Delay Valve: Description and Operation
PURPOSE
On most models, a time delay device is incorporated into the EGR system which works in conjunction with the idle enrichment system to improve
engine starting and performance.
OPERATION
This System consists of an electronic timer and either one or two vacuum solenoids. The electronic timer energizes the solenoid(s) during starting
and for 35 seconds thereafter. When the solenoid(s) energize(s), vacuum to the EGR amplifier is cut off, thereby stopping exhaust gas
recirculation.
At the same time, vacuum is applied to the idle enrichment system through the solenoid and or a block coolant valve when the engine block
temperature is below 98° F., for California models or 150° F., for all other models. On all except V8-360 engines, idle enrichment is controlled
only by engine coolant temperature. The system used on V8-360 engines except California models, functions basically in the same manner except
that it uses two vacuum solenoids, one controlling the EGR system, the other controlling the idle enrichment system. Thirty five seconds after
engine start up, the solenoid(s) de-energize(s), allowing normal EGR operation and stopping idle enrichment.
