System Checking

Following difficulties may indicate a malfunctioning PCV valve:

1. Engine stalls frequently after stops, runs rough after restart.
2. Engine loses power and surges at speeds above idle.
3. Engine has rich rolling idle, produces black smoke at tailpipe.
4. Idle speed fluctuates, but engine does not stall.

Fig 1: 1964-65 CLOSED POSITIVE VENTILATION SYSTEM (V8)

Courtesy of GENERAL MOTORS COMPANY