Inspection Procedure 1 : Engine Malfunctions Due to Insufficient Fuel Supply: Diagnosis

Required Special Tools: 

• 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. STEP 1. Using scan tool MB991958, read the MFI system diagnostic trouble code. 
   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.
   1. Ensure that the ignition switch is at the "LOCK" (OFF) position.
   2. Start up the personal computer.
   3. Connect special tool MB991827 to special tool MB991824 and the personal computer.
   4. Connect special tool MB991910 to special tool MB991824.
   5. Connect special tool MB991910 to the data link connector.
   6. Turn the power switch of special tool MB991824 to the "ON" position.
      NOTE: When special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color.
   7. Start the M.U.T.-III system on the personal computer.
   8. Turn the ignition switch to the "ON" position.
   9. Check for MFI system diagnostic trouble code (Refer to MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS ).
   10. Turn the ignition switch to the "LOCK" (OFF) position, and then remove scan tool MB991958 in the reverse order of installation.
       Fig 1: Connecting Special Tool MB991910 To Data Link Connector

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       Q: Is the DTC set? 

       1. YES:  Repair MFI system (Refer to DIAGNOSTIC TROUBLE CODE CHART ). Then go to Step  6.
       2. NO:  Go to Step 2.
2. STEP 2. Check the fuel pressure. 

   Release residual pressure from the fuel line to prevent fuel spray (Refer to FUEL PRESSURE TEST ).

   Q: Is the fuel pressure in good condition? 

   1. YES:  Go to Step  5.
   2. NO:  Go to Step 3.
3. STEP 3. Check for bending, twisting or clogging of the fuel main pipe and fuel high-pressure hose. 

   Q: Are the fuel main pipe and fuel high-pressure hose in good condition? 

   1. YES:  Go to Step 4.
   2. NO:  Repair or replace the fuel main pipe or fuel high-pressure hose. Then go to Step  6.
      Fig 2: Checking For Bending, Twisting Or Clogging Of Fuel Main Pipe And Fuel High-Pressure Hose

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Check the fuel pump operation. 

   Refer to FUEL PUMP OPERATION CHECK .

   Q: Is the fuel pump module operation in good condition? 

   1. YES:  Go to Step 5.
   2. NO:  Replace the fuel tank pump and gauge assembly (Refer to FUEL PUMP OPERATION CHECK  ). Then go to Step  6.
5. STEP 5. Check the inside of the fuel tank for contamination and rust. 

   Remove the fuel tank (Refer to FUEL TANK  ).

   Q: Is the fuel tank in good condition? 

   1. YES:  Go to Step 6.
   2. NO:  Replace the fuel filter, and clean the fuel tank and fuel line. Then go to Step 6.
6. STEP 6. Retest the system. 

   Q: Is the engine malfunction eliminated? 

   1. YES:  The procedure is complete.
   2. NO:  Return to Step  1.