Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

Carburetor Switch

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See Figure 1

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Fig. Fig. 1: The carburetor switch is located on the bottom end of the throttle kicker, as shown

OPERATION



Chrysler Electronic Spark Control (ESC) and Mikuni Feedback Carburetor Systems

The ESC system is used only on 2.2L carbureted engines. The Mikuni feedback carburetor system is used only on 2.6L engines.

The carburetor switch is located at the end of the idle stop solenoid. The primary purpose of the switch is to inform the computer when the engine is at idle or off-idle. When the carburetor switch is closed at idle, the computer cancels the spark advance and the idle control circuit adjusts the air/fuel ratio.

TESTING



Chrysler Electronic Spark Control (ESC) System

Grounding carburetor switch eliminates all spark advance on most systems.

  1. With ignition key in OFF position, disconnect 10-way connector from Spark Control Computer.
  2.  
  3. With throttle completely closed, check continuity between pin 7 of disconnected 10-way connector and a good engine ground. Continuity should exist.
  4.  



If continuity does not exists, check the wiring between the ESC computer and carburetor switch.
 
If continuity does exist, proceed to the next step.
 

  1. With throttle open, check continuity between pin 7 of disconnected 10-way connector and a good engine ground. There should be no continuity.
  2.  
  3. If the switch fails to perform as specified, replace the switch and retest.
  4.  

Chrysler Mikuni Feedback Carburetor System
  1. Disconnect the electrical connector from the carburetor switch.
  2.  
  3. Connect an ohmmeter between the switch connector and a known good engine ground.
  4.  
  5. Operate the throttle linkage while observing the ohmmeter.
  6.  



With the throttle plates opened continuity should NOT exist
 
With the throttle plates fully closed continuity should exist
 

  1. If the sensor did not operate as specified, replace the switch and retest.
  2.  

REMOVAL & INSTALLATION



The carburetor switch is located on the end of the idle stop solenoid. If the carburetor switch is deemed faulty, the entire idle stop solenoid must be replaced.

  1. Disconnect the negative battery cable.
  2.  
  3. Disengage the electrical wiring harness connectors from the carburetor switch.
  4.  
  5. Loosen and remove the idle stop solenoid bracket mounting bolt.
  6.  
  7. Remove the solenoid from the carburetor.
  8.  

To install:
  1. Place the idle stop solenoid against the carburetor in its original position.
  2.  
  3. Install the mounting bolt and tighten it until secure.
  4.  
  5. Attach the electrical wiring harness connectors to the carburetor switch and idle stop solenoid.
  6.  
  7. Connect the negative battery cable.
  8.  
  9. Adjust the carburetor switch as follows:
    1. Check the ignition timing and adjust, if necessary.
    2.  
    3. With the engine fully warmed up, place the transaxle in Neutral and set the parking brake. Turn all electrical accessories OFF .
    4.  
    5. Ground the idle stop carburetor switch with a jumper wire.
    6.  
    7. Remove the red wire from the 6-way connector on the carburetor side of the connector.
    8.  
    9. Adjust the throttle stop screw until the engine speed reaches 700 rpm.
    10.  
    11. Reattach the wire at the connector and remove the jumper wire from the idle stop carburetor switch.
    12.  

  10.  

 
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