Toyota Tercel 1984-1994 Repair Guide

PCV Valve

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The PCV valve regulates crankcase ventilation during various engine operating conditions. At high vacuum (idle speed and partial load range) it will open slightly and at low vacuum (full throttle) it will open fully. This causes vapor to be removed from the crankcase by the engine vacuum and then sucked into the combustion chamber where it is burned.

REMOVAL & INSTALLATION



See Figures 1, 2, 3 and 4

  1. Check the ventilation hoses for leaks or clogging. Clean or replace as necessary.
  2.  
  3. Locate the PCV valve in the cylinder head cover or in the manifold-to-crankcase line. Pull the valve out from the cover, then remove it from the hose.
  4.  
  5. Blow into the cylinder head side of the valve. There should be a free passage of air through the valve.
  6.  
  7. Blow into the intake manifold end of the valve. There should be little or no passage of air through the valve.
  8.  
  9. If the PCV valve failed either of the preceding two checks, it will require replacement.
  10.  
  11. Installation is in the reverse order of removal procedure.
  12.  

On some models with fuel injection there is no PCV valve. The vapor passage in the ventilation lines is controlled by two orifices. To check the PCV system on these models, inspect the hoses for cracks, leaks or other damage. Blow through the orifices to make sure they are not blocked. Replace all components as necessary.

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Fig. Fig. 1: Air should not flow through the PCV valve when blowing through the intake manifold side



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Fig. Fig. 2: Air should pass through the PCV valve when blowing through the cylinder head side



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Fig. Fig. 3: Removing the PCV valve from the valve cover



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Fig. Fig. 4: Be sure to insert the correct end of the PCV valve into the hose

 
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