ENGINE TUNE-UP [MZI-3.7]

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  Note
  • If the accelerator pedal is depressed continuously for a specified time, the engine speed may decrease to the idle speed. This is due to the fuel cut control operation, which prevents overheating, and it does not indicate a malfunction.

Engine Tune-up Preparation

1. Verify that the selector lever is in the P position.

2. Connect the M-MDS to the DLC-2.

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3. Turn off the electrical loads.

4. Verify that no DTCs are available.

5. Warm up the engine as follows.

  (1) Start the engine.

  (2) Perform no-load racing at 2,500—3,000 rpm for 3 min. (ECT is approx. 80 °C {176 °F} or more)

  (3) Release the accelerator pedal.

  (4) Wait until the cooling fans stop.

Ignition Timing Inspection

1. Perform “Engine Tune-up Preparation”. (See Engine Tune-up Preparation.)

  Note
  • The ignition timing cannot be adjusted.
  • The M-MDS is required to verify the ignition timing.

2. Verify that the ignition timing (M-MDS: SPARKADV) is within the specification using M-MDS function.

  Ignition timing

  Approx. BTDC 13 °

3. Verify that ignition timing advances when the engine speed increases gradually.

  • If it is not within the specification, refer to “ENGINE SYMPTOM TROUBLESHOOTING”. (See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)

Idle Speed Inspection

1. Perform “Engine Tune-up Preparation”. (See Engine Tune-up Preparation.)

  Note
  • The idle speed cannot be adjusted.
  • The M-MDS is required to verify the idle speed.

2. Verify that the idle speed (M-MDS: RPM) is within the specification using M-MDS.

  Idle speed (N position)

  No load: 550—650 rpm
  Electrical load on: 550—730 rpm
  Power steering oil pump operation: 580—680 rpm
  A/C and heater operation: 570—745 rpm

Idle Mixture Inspection

1. Perform “Engine Tune-up Preparation”. (See Engine Tune-up Preparation.)

2. Verify that the idle speed and ignition timing are within the specification. (See Ignition Timing Inspection.)(See Idle Speed Inspection.)

3. Insert an exhaust gas analyzer into the tailpipe.

4. Verify that the CO and HC concentrations are within the specified regulation.

  • If not within the regulation, refer to “ENGINE SYMPTOM TROUBLESHOOTING”. (See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)

  CO concentration

  Within the regulation

  HC concentration

  Within the regulation