Chrysler DODGE D150 1993 Service Manual page 1485

EMISSION CONTROL SYSTEMS

Fig. 5 Typical Closed Crankcase Ventilation System

J 9 0 2 5 - 2 0

Fig. 6 Engine Off or Engine PopBack—No Vapor

Fig. 7 High Intake Manifold Vacuum—Minimal Vapor

During periods of moderate manifold vacuum, the

plunger is only pulled part way back from inlet. This

results in maximum vapor flow through the valve

Fig. 8 Moderate Intake Manifold Vacuum—Maximum

(1) With engine idling, remove the PCV valve from

cylinder head (valve) cover. If the valve is not

plugged, a hissing noise will be heard as air passes

through the valve. Also, a strong vacuum should be

felt at the valve inlet (Fig. 9).

Fig. 9 Check Vacuum at PCV Valve—Typical

(2) Install the PCV valve. Remove the crankcase

breather/filter. Hold a piece of stiff paper, such as a

parts tag, loosely over the opening of crankcase

breather/filter at the cylinder head (valve) cover (Fig.

(3) The paper should be drawn against the opening

in the cylinder head (valve) cover with noticeable

force. This will be after allowing approximately one

minute for crankcase pressure to reduce.

CRANKCASE BREATHER — REMOVED

Fig. 10 Check Vacuum at Crankcase Breather

Opening—Typical

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