Mazda 3 Service Manual: Engine Tune Up [Mzr 2.3 Disi Turbo]

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 shift lever is in neutral position.

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

3. Verify that no DTCs are available.

4. Warm up the engine (ECT is approx. 80°C {176 °F} or more

).

5. Turn off all electrical loads.

6. Wait until the cooling fan stops.

Ignition Timing Inspection

NOTE:

• The ignition timing cannot be adjusted.

• The M-MDS is required to verify the ignition timing.

1. Complete the engine tune-up preparation..

2. Verify the ignition timing (M-MDS: SPARKADV) using the PID/data monitor function of the M-MDS..

Ignition timing

• Approx. BTDC 10°

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

• If there is malfunction, refer to “ENGINE SYMPTOM TROUBLESHOOTING”..

Idle Speed Inspection

NOTE:

• The idle speed cannot be adjusted.

• The M-MDS is required to verify the idle speed.

1. Complete the engine tune-up preparation..

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

• If there is malfunction, refer to “ENGINE SYMPTOM TROUBLESHOOTING”..

Idle speed

• No load: 650—750 rpm

• Electrical load on*1: 650—750 rpm

• A/C on: 700—800 rpm

Idle Mixture Inspection

1. Verify that the idle speed and ignition timing are within the specification..

2. Insert an exhaust gas analyzer to the tailpipe.

3. Verify that the CO and HC concentrations are within the regulation.

Idle mixture

• HC concentration: Within the regulation

• CO concentration: Within the regulation