Cherokee 2WD L4-150 2.5L VIN H TBI (1988)
Positive Crankcase Ventilation: Testing and Inspection
CCV System
With engine idling, remove the metered orifice from rocker cover. If the metered orifice is not plugged, a hissing sound will be heard as air passes
through the orifice, and a strong vacuum should be felt when a finger is placed over the inlet of the orifice. If no noise is heard, it will be necessary to
clean the passage in the metered orifice and the lower part of the throttle body. Also, the hose will have to be cleaned or replaced.
