Cherokee 4WD L6-242 4.0L VIN M FI (1988)
Positive Crankcase Ventilation: Description and Operation
CCV System
The CCV system is similar to a conventional PCV system, but does not use a vacuum controlled valve. When the engine is operating, fresh air enters the
crankcase and mixes with crankcase vapors. Manifold vacuum draws the vapors through a metered orifice (2.6 MM) and into the intake manifold. The
vapors then mix with the air-fuel mixture and are burned in the combustion chamber.
