Ignition Timing Check

Required Special Tools: 

• MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
• MB992745: V.C.I.-Lite main harness A
• MB992747: V.C.I.-Lite USB cable short
• MB992748: V.C.I.-Lite USB cable long
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicles Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

1. Before inspection, set the vehicle to the pre-inspection condition.
   CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
2. Turn the ignition switch to the "LOCK" (OFF) position and then connect scan tool (M.U.T.-III) to the data link connector. (Refer to DIAGNOSTIC FUNCTION ).
3. Set the timing light to the power supply line (terminal No. 3) of the ignition coil No. 2.
   NOTE: The power supply line is looped and also longer than the other ones.
4. Start the engine and run it at idle.
5. Check that the idle speed is approximately 600 r/min.
6. Select scan tool (M.U.T.-III) actuator test "item number 11".
7. Check that basic ignition timing is within the standard value.

   Standard value: 5° BTDC ± 3° 

8. If the basic ignition timing is not within the standard value. (Refer to SYMPTOM CHART ).
   CAUTION: If the actuator test is not canceled, the forced drive will continue for 27 minutes. Driving in this state could lead to engine failure.
9. Cancel the setting mode of the scan tool (M.U.T.-III).
10. Check that the actual ignition timing is at the standard value.

    Standard value: Approximately 10° BTDC 

    NOTE: The ignition timing fluctuates about ± 7°, even under normal operating condition.
    NOTE: It is automatically further advanced by about 5° from 10° Before Top Dead Center at higher altitudes.
    NOTE: Wait till approximately 1 minute passes after the engine started, and check the ignition timing when the engine stabilized.
11. Remove the timing light.
    Fig 1: Identifying Ignition Timing Pickup Loop

    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
12. Turn the ignition switch to the "LOCK" (OFF) position and then disconnect the scan tool (M.U.T.-III).