Toyota Cressida/Corona/Crown/MarkII 1970-1982 Repair Guide

Carburetor Auxiliary Slow System

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OPERATION



A carburetor auxiliary slow system is used on 1970-71 2M engines. It provides uniform combustion during deceleration. The components of the auxiliary slow system consist of a vacuum operated valve, a fresh air intake, and a fuel line which is connected to the carburetor float chamber.

During deceleration, manifold vacuum acts on the valve which opens it causing additional air/fuel mixture to flow into the intake manifold.

REMOVAL & INSTALLATION



  1. Remove the hoses from the auxiliary slow system.
  2.  
  3. Unfasten the recessed screws and remove the system as a unit.
  4.  
  5. Installation is the reverse of removal.
  6.  

TESTING





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Fig. Fig. 1 Testing the carburetor auxiliary slow system diaphragm

  1. Start the engine and run it to normal operating temperature.
  2.  
  3. Remove the rubber cap from the diaphragm and place your finger over the opening. There should be no vacuum at idle speed. If there is, the diaphragm must be replaced.
  4.  
  5. Pinch the air intake hose which runs from the air cleaner to the auxiliary slow system. There should be no change in the engine idle with the hose pinched.
  6.  
  7. Disconnect the air intake hose at the auxiliary slow system. Race the engine. Place your finger over the air intake. Release the throttle. Suction should be felt at the air intake.
  8.  
  9. If any of the tests indicate a failed component, replace the system as a unit.
  10.  

 
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