System Inspection
WARNING: This page is about a different car, the 1995 Mazda B4000, 1995 Mazda B3000, and 1995 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
Warm engine to normal operating temperature, and operate it at idle. Pull PCV valve with hose attached, from valve cover. Put finger over PCV valve opening and check for vacuum. If no vacuum is felt, check for collapsed line and blockage. Replace valve as necessary.