Curb Idle Speed Check

Required Special Tool: 

MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.I.C.
• MB991827: USB Cable
• MB991911: Main Harness B

1. Before inspection, set vehicle to the following conditions:
   • Engine coolant temperature: 80-95°C (176-203°F)
   • Lights and all accessories: OFF
   • Transaxle: Neutral
   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. 
2. Connect scan tool MB991958 to the data link connector.
3. Confirm basic ignition timing is within the standard value. (Refer to IGNITION TIMING CHECK  .)
   1. Standard value: 5° BTDC +/- 3° 
4. Start the engine.
5. Run the engine at idle for 2 minutes.
6. Check the idle speed. Select MFI service data item number 22 and take a reading of the idle speed.
   1. Curb idle speed: 850 +/- 100 r/min 
   NOTE: The idle speed is controlled automatically by the idle air control system.
7. If the idle speed is outside the standard value, refer to SYMPTOM CHARTS .
   Fig 1: Connecting Scan Tool MB991958 To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.