Positive Crankcase Ventilation (Pcv) System - Toyota 4-Runner 1985 Repair Manual

EC-4 EMISSION CONTROL SYSTEMS (EFI) - Positive Crankcase Ventilation (PCV) System
POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM
Ventilation Hose
PCV Valve
Flame Arrester
To reduce HC emissions, crankcase blow-by gas (He) is routed through the PCV valve to the intake manifold for
combustion in the cylinders.
Engine not Running or Backfiring
Intake Manifold Side
OPCV VALVE IS CLOSED.
Cylinder Head Side
EC1013
Idling or Decelerating
OPCV VALVE IS OPEN.
OVACUUM PASSAGE IS SMALL.
EC1015
Normal Operation
OPCV VALVE IS OPEN.
oVACUUM PASSAGE IS
LARGE.
Acceleration or Heavy Load
OPCV VALVE IS FULLY
OPEN.
EC1036
EC1014
EC1016