Toyota Camry 1983-1996 Repair Guide

Dash Pot (DP) System

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SYSTEM OPERATION



See Figure 1

The operation of this system reduces the HC and CO emissions. When decelerating, the dash pot opens the throttle valve slightly more than at idle. This causes the air-fuel mixture to burn completely. This system is only applicable to the 1989-91 2VZ-FE engines.



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Fig. Fig. 1: Dash Pot system operation-2VZ-FE engines

ADJUSTMENT



  1. Warm up and stop engine.
  2.  
  3. Check idle speed.
  4.  
  5. Disconnect the throttle cables from the throttle cam.
  6.  
  7. Remove the VTV cap, filter and separator from the dash pot.
  8.  
  9. Adjust DP setting speed as follows:
    1. Race the engine at 2500 rpm for a few seconds. Plug the VTV hole with your finger in the dash pot assembly.
    2.  
    3. Release the throttle valve.
    4.  
    5. Check the DP setting speed. The DP setting speed is 2000 rpm with cooling fan OFF.
    6.  
    7. Adjust the DP setting speed by turning the DP adjusting screw.
    8.  

  10.  
  11. Reinstall the DP separator, filter and VTV cap.
  12.  
  13. Connect the throttle cables to the throttle cam.
  14.  
  15. Check system operation by racing the engine at 2500 rpm for a few seconds, release the throttle valve and check that the engine returns to idle speed in a few seconds.
  16.  

REMOVAL & INSTALLATION



  1. To remove the dash pot assembly, unplug the vacuum hose then remove the dash pot mounting screws.
  2.  
  3. Remove the assembly from the throttle body.
  4.  
  5. Installation is the reverse of removal. Replace the dash pot assembly and adjust if necessary.
  6.  

 
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