Grand Cherokee 4WD L6-242 4.0L VIN S MFI (1993)
Air Cleaner Housing: Description and Operation
Canister Purge Operation
Air Cleaner Venturi
PURPOSE
The air cleaner assembly contains a venturi, which is the purge vacuum source for the charcoal canister.
OPERATION
Purge operation is controlled by the purge shutoff switch. The purge switch opens when manifold vacuum is applied. Air flow across the venturi
increases with engine speed, creating a low pressure area around the purge inlet slots. When the purge switch is open, vapors are drawn into the
incoming airstream where they are burned during combustion.