Toyota Camry 1983-1996 Repair Guide

Idle Speed and Mixture Adjustment

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IDLE SPEED ADJUSTMENT



Gasoline Engines

Follow the correct service adjustment procedure for your engine. Review the complete procedure before starting.

One of the merits of electronic fuel injection is that it requires so little adjustment. The computer (ECM) does most of the work in compensating for changes in climate, engine temperature, electrical load and driving conditions. The idle on the fuel injected engines should be checked periodically (15,000 miles or 24 months) but not adjusted unless out of specifications by more than 50 rpm.

The idle speed adjusting screw is located on the side of the throttle body. You can find the throttle body by following the accelerator cable to its end. The adjusting screw may have a cap over it. If so, pop the cap off with a small screwdriver.

If for any reason the idle cannot be brought into specification by this adjustment procedure, return the screw to its original setting and follow other diagnostic procedures to find the real cause of the problem. Do not try to cure other problems with this adjustment.

2S-ELC ENGINE

See Figures 1 and 2

  1. Leave the air cleaner installed and all the air pipes and hoses of the air intake system connected. Leave all vacuum lines connected to the ESA and EGR systems, ect.
  2.  
  3. Make sure that the electronic fuel injection system wiring connectors are fully plugged in. Apply the emergency brake and block the wheels. Start the engine and allow it to warm up.
  4.  
  5. Turn all the accessories off and place the transaxle in the Neutral range.
  6.  
  7. Remove the rubber cap from the IIA service connector coming from the distributor. Remove the plug covering the idle speed adjusting screw. Place a cap and the plug in your pocket. Do not loose them.
  8.  
  9. Attach the test probe of the tachometer to the service connector. Please refer to the illustrations in the Ignition Timing.
  10.  


WARNING
Never allow the tachometer terminal to touch the ground as it could result in damage to the Igniter and/or the ignition coil.

  1. Race the engine at 2500 rpms for approximately two minutes. Return the engine to idle and disconnect the Vacuum Switching Valve (VSV) for the Idle Speed Control (ISC).
  2.  



Click image to see an enlarged view

Fig. Fig. 1: Disconnect the Idle Speed Control (ISC) valve-2S-ELC engine

  1. Set the idle speed by turning the adjusting screw. Check the Tune-up chart or label under the hood for the correct speed.
  2.  



Click image to see an enlarged view

Fig. Fig. 2: The idle speed screw is located on the throttle body

  1. After setting the idles speed, shut the engine off. Connect the VSV connector and remove the tachometer. Install the plug and the rubber cap.
  2.  

3S-FE ENGINE

See Figure 2

  1. Leave the air cleaner installed and all the air pipes and hoses of the air intake system connected. Leave all vacuum lines connected to the ESA and EGR systems, ect.
  2.  
  3. Make sure that the electronic fuel injection system wiring connectors are fully plugged in. Apply the emergency brake and block the wheels. Start the engine and allow it to warm up.
  4.  
  5. Turn all the accessories off and place the transaxle in the Neutral range.
  6.  
  7. Remove the rubber cap from the IIA service connector coming from the distributor. Remove the plug covering the idle speed adjusting screw. Place a cap and the plug in your pocket. Do not loose them.
  8.  

These engines require the use of a special tachometer that can be attached to this service connector. Many tachometers are not compatible with this hook-up, so it is recommended that you consult your manufacture before purchasing a certain type.

  1. Connect the test probe of the tachometer to the service connector. Please refer to the illustrations in the Ignition Timing.
  2.  


WARNING
Never allow the tachometer terminal to touch the ground as it could result in damage to the Igniter and/or the ignition coil.

  1. Open the lid of the check connector. Using a suitable jumper wire, short the E1 and T terminals on 1987-88 models and E1 and TE1 terminals on the 1988-91 models.
  2.  
  3. Check the idle speed by turning the idle adjusting screw. The idle speed should be as specified in the Tune-up chart or on your label under the hood.
  4.  
  5. Remove the jumper wire and close the lid of the service connector. Disconnect the tachometer and install the plug and rubber boot.
  6.  

1994 1MZ-FE AND 1992-95 5S-FE ENGINES
  1. Idle speed adjustment is performed under the following conditions:

    Engine at normal operating temperature
     
    Air cleaner installed
     
    Air pipes and hoses of the air induction and EGR systems properly connected
     
    All vacuum lines and electrical wires connected and plugged in properly
     
    All electrical accessories in the OFF position
     
    Transaxle in the N position
     

  2.  
  3. Connect a tachometer to the engine. Connect the probe of the tachometer to terminal IG- of the check connector.
  4.  
  5. Run the engine at 2500 rpm for 90 seconds.
  6.  
  7. Short the check connector at terminals TE1 and E1 using a suitable jumper wire or special service tool 09843-18020.
  8.  
  9. Adjust the idle speed by turning the idle speed adjusting screw to specification.
  10.  

Refer to underhood emission sticker to confirm idle speed specification. Always follow the emission sticker specification.

  1. Remove the jumper wire or special service tool from the connector terminals.
  2.  
  3. Disconnect the tachometer. Road test the vehicle for proper operation.
  4.  

1995-96 1MZ-FE, 1996 5S-FE ENGINES, 2VZ-FE AND 3VZ-FE ENGINES

Idle speed on these engines is controlled completely by the Electronic Control Module (ECM). The idle speed is not adjustable on these engines.

Diesel Engines

See Figures 3 and 4

  1. This adjustment should be made with the engine at normal operating temperature under the following conditions:
    1. Air cleaner installed
    2.  
    3. All accessories are off
    4.  
    5. Transaxle in Neutral
    6.  
    7. Wheels blocked and the parking brake firmly applied
    8.  

  2.  
  3. Connect a suitable diesel tachometer to the engine according to the manufactures instructions.
  4.  
  5. Disconnect the accelerator cable from the injection pump.
  6.  



Click image to see an enlarged view

Fig. Fig. 3: Disconnecting the injection pump accelerator pump

  1. Start the engine and allow it to warm up.
  2.  
  3. Check the idle speed with the tachometer. It should be 750 rpms. If not, adjust the idle speed by loosening the locknut and turning the idle speed adjusting screw located on the injection pump.
  4.  



Click image to see an enlarged view

Fig. Fig. 4: Idle speed adjustment

MAXIMUM SPEED ADJUSTMENT



This procedure applies to diesel engines only.

  1. This adjustment should be made with a warm engine under the following conditions:
    1. Air cleaner installed
    2.  
    3. All accessories are off
    4.  
    5. Transaxle in Neutral
    6.  
    7. Wheels blocked and the parking brake firmly applied
    8.  

  2.  
  3. Connect a suitable diesel tachometer to the engine according to the manufactures instructions.
  4.  
  5. Disconnect the accelerator cable from the injection pump.
  6.  
  7. Check the normal idle speed and adjust as necessary.
  8.  
  9. Fully depress the injection pump adjusting lever, then check the maximum idle speed with the tachometer. The maximum idle speed should be 5200 rpms.
  10.  


WARNING
This check should be done quickly. Hold the lever in the maximum idle position just long enough to read the tachometer and perform any necessary adjustments.

  1. If the maximum idle speed is not as specified, perform the following adjustment:
    1. Remove the lockwire on the maximum adjusting screw.
    2.  
    3. Loosen the locknut on the maximum adjusting screw.
    4.  
    5. Adjut the maximum idle speed by turning the screw.
    6.  
    7. When the maximum idle speed is adjusted, tighten the locknut.
    8.  
    9. Locjk the maximum adjusting screw with a new piece of wire.
    10.  

  2.  
  3. Check the normal idle speed and adjust as necessary. Recheck the maxim idle speed.
  4.  
  5. Disconnect the tachometer.
  6.  
  7. Connect the accelerator cable to the adjusting lever so that there is not slack in the cable.
  8.  
  9. Depress the accelerator pedal all the way and have an assistant observe the adjusting lever on the injection pump. The adjusting lever should be stopped by the maximum idle speed adjusting bolt when the pedal is fully depressed.
  10.  

See Figures 5 and 6



Click image to see an enlarged view

Fig. Fig. 5: Gasoline Engine Tune-Up Specifications



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Fig. Fig. 6: Diesel Engine Tune-Up Specifications

 
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