[13B] MULTIPORT FUEL INJECTION (MPI) <4G64> - - TROUBLESHOOTING - SYMPTOM PROCEDURES - Inspection Procedure 12: Hesitation, Sag, Poor Acceleration, Stumble or Surge | PRINT PAGE / INDEX / PRIOR / NEXT

Inspection Procedure 12: Hesitation, Sag, Poor Acceleration, Stumble or Surge
COMMENT ON TROUBLE SYMPTOM Failure is possibly caused by failed ignition system, improper air-fuel ratio, improper compression pressure or other faults.
PROBABLE CAUSE Failed air-fuel ratio control system Failed ignition system Failed fuel system Failed intake and exhaust system Failed emission control system Throttle valve fouled Improper compression pressure Failed engine-A/T-ECU
| DIAGNOSIS PROCEDURE
| STEP 1. MUT-II/III diagnosis code Q: Diagnosis code set? YES: Inspection chart for diagnosis code (Refer to ). NO: Go to Step 2 .
| STEP 2. Check injector for operating sound. Check injector for operating sound (Refer to ). Q: Can operating sound be heard? YES: Go to Step 3 . NO: Check the injector system of the defective cylinder (Refer to code No. 41 injector system ).
| STEP 3. MUT-II/III data list Refer to Data list reference table . Item 13: Intake air temperature sensor Item 14: Throttle position sensor Item 21: Engine coolant temperature sensor Item 25: Barometric pressure sensor Q: Are the check results normal? YES: Go to Step 4 . NO: Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data value (Refer to Inspection Chart for Diagnosis Codes ).
| STEP 4. Check EGR control solenoid valve itself. Check EGR control solenoid valve itself [Refer to GROUP 17 - Emission Control System - Exhaust Gas Recirculation (EGR) System ]. Q: Is the check result normal? YES: Go to Step 5 . NO: Replace EGR control solenoid valve.
| STEP 5. Check EGR valve itself. Check EGR valve itself (Refer to GROUP 17 - Emission Control System - Exhaust Gas Recirculation (EGR) System ). Q: Is the check result normal? YES: Go to Step 6 <Vehicle without catalytic converter>. NO: Replace EGR valve.
| STEP 6. Connector check: B-110 and B-111 ignition coil connectors
| Q: Is the check result normal? YES: Go to Step 7 . NO: Repair.
| STEP 7. Check ignition coil spark. Q: Is the check result normal? YES: Go to Step 12 . NO: Go to Step 11 .
| STEP 8. Check spark plug. Q: Is the check result normal? YES: Go to Step 9 . NO: Replace spark plug.
| STEP 9. Check spark plug cable itself. Check spark plug cable itself (Refer to GROUP 16 - Ignition System - On-vehicle Service ). Q: Is the check result normal? YES: Go to Step 10 . NO: Replace spark plug cable.
| STEP 10. Check ignition coil itself. Check ignition coil itself (Refer to GROUP 16 - Ignition System - On-vehicle Service ). Q: Is the check result normal? YES: Go to Step 11 . NO: Replace ignition coil.
| STEP 11. Check harness between terminal No. 2 of ignition coil connector of each cylinder and body earth.
| Check earthing line for open circuit and damage. Q: Is the check result normal? YES: Check and repair harness between terminal No. 3 of ignition coil connector of each cylinder and C-112 engine-A/T-ECU Check signal line for open/short circuit and damage. NO: Repair.
| STEP 12. Check throttle body (throttle valve portion) for contamination. Q: Is the check result normal? YES: Go to Step 13 . NO: Clean throttle body (throttle valve portion) (Refer to ).
| STEP 13. Measure fuel pressure. Measure fuel pressure (Refer to ). Q: Is the check result normal? YES: Go to Step 14 . NO: Repair.
| STEP 14. Check compression pressure. Check compression pressure (Refer to GROUP 11A - On-vehicle Service ). Q: Is the check result normal? YES: Replace engine-A/T-ECU. NO: Repair.

[13B] MULTIPORT FUEL INJECTION (MPI) <4G64> - - TROUBLESHOOTING - SYMPTOM PROCEDURES - Inspection Procedure 12: Hesitation, Sag, Poor Acceleration, Stumble or Surge | PRINT PAGE / INDEX / PRIOR / NEXT

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