Manifold Vacuum Check

Required Special Tool: 

MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V. C. I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A

1. Before inspection, set the vehicle in the following condition:
   • Engine coolant temperature: 80 - 95°C (176 - 203°F)
   • Lights and all accessories: OFF
   • Transaxle: Neutral (P range on vehicles with TC-SST)
     NOTE: On vehicles for Canada, the headlight, taillight, etc. remain lit even when the lighting switch is in "OFF" position but this is no problem for checks.
     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.
   Fig 1: Connecting Scan Tool MB991958 To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. Disconnect the ventilation hose from the positive crankcase ventilation (PCV) valve, and then connect a vacuum gauge to the ventilation hose. Plug the PCV valve.
Fig 2: Identifying Vacuum Gauge, PCV Valve And Plug
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Start the engine and check that idle speed is approximately 700 r/min.
5. Check the intake manifold vacuum.

   Limit: Minimum 60 kPa (18 in Hg) 

6. Turn off the ignition switch.
7. Remove the vacuum gauge and then connect the ventilation hose to the PCV valve.
   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.
8. Disconnect scan tool MB991958 from the data link connector.