Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Canister Purge Solenoid: Description and Operation
Computer Command Control (C3) System
ECM controls vacuum to the purge valve through the purge solenoid.
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When the engine is cold (open loop), the solenoid valve is energized, blocking vacuum to the purge valve.
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When the engine is warm (closed loop) and operating above a preset engine or vehicle speed the solenoid valve is de-energized, allowing
vacuum to be applied to the purge valve.
