Toyota Pick-ups/Land Cruiser/4Runner 1989-1996

PCV Valve

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See Figure 1

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 along with the fuel.



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Fig. Fig. 1: The PCV valve regulates crankcase ventilation according to engine running conditions

The PCV system will not function properly unless the oil filler cap is tightly sealed. Check the gasket on the cap and be certain it is not leaking. Replace the cap or gasket or both if necessary to ensure proper sealing.

REMOVAL & INSTALLATION



See Figures 2 and 3

  1. Check the ventilation hoses and lines for leaks or clogging. Clean or replace as necessary.
  2.  
  3. Locate the PCV valve in the cylinder head cover and remove it by pulling it upward.
  4.  



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Fig. Fig. 2: Locate the PCV valve in the cylinder head cover and remove it by pulling it upward

  1. Test the valve by attaching a clean tube to the crankcase end of the valve, then blow through it. There should be free passage of air through the valve.
  2.  
  3. Move the tube to the other end of the valve. Blow into the tube. There should be little or no passage of air through the valve.
  4.  
  5. If the PCV valve failed either of the preceding two checks, it will require replacement.
  6.  
  7. Pull the PCV valve off the hose.
  8.  



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Fig. Fig. 3: Pull the PCV valve off the hose

To install:
  1. Slip the hose back onto the proper end of the PCV valve.
  2.  
  3. Press the valve into the retaining grommet in the cylinder head cover.
  4.  

 
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