PL720 2WD L4-1952cc 2.0L SOHC (Z20) (1985)
Positive Crankcase Ventilation: Testing and Inspection
Fig. 3 Testing PCV valve (typical)
With engine running at idle, remove the ventilator hose from PCV valve; if the valve is working, a hissing noise will be heard as air passes through the
valve and a strong vacuum should be felt immediately when a finger is placed over valve inlet, Fig. 3.