Toyota Celica/Supra 1971-1985 Repair Guide

Choke Breaker (CB) System

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INSPECTION



See Figures 1 and 2



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Fig. Fig. 1: Exploded view of the choke housing



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Fig. Fig. 2: When the engine is cold, the spring contacts and closes the choke valve. When hot, the spring expands and opens the choke valve

US Models

See Figure 3



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Fig. Fig. 3: On US models, remove the hose coming from the 3-way connection

This system performs the same function that the previous one does except that it goes one step further and forces the choke valve to open up even further after the engine has warmed up.

  1. Carefully note the position of the choke breaker linkage rod.
  2.  
  3. Disconnect the vacuum hose between the choke breaker diaphragm and the 3-way connector at the diaphragm side.
  4.  
  5. Start the engine and check that the choke breaker linkage moves from its former position.
  6.  
  7. Reconnect the vacuum hose to the diaphragm. The linkage should move even further than it was.
  8.  
  9. Check the VSV and the TVSV as detailed under Evaporative Emission Control in Driveability & Emission Controls .
  10.  

Canadian Models

See Figures 4 and 5



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Fig. Fig. 4: When the vacuum hose is detached on Canadian models, the choke linkage should move



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Fig. Fig. 5: Once the hose is connected, the linkage should return to its original position

The choke breaker system is used to monitor the automatic choke system. To prevent too rich a mixture when the choke is closed, the choke breaker forces the choke valve open slightly.

  1. Start the engine.
  2.  
  3. Disconnect the hose from the choke breaker diaphragm and check that the choke linkage returns to its previous position.
  4.  
  5. Reconnect the hose to the diaphragm and check that the choke linkage is pulled back by the diaphragm.
  6.  

 
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