No. 28 Spark Plug Condition: Procedure

1. Remove all spark plugs.

   Refer to REMOVAL

2. Inspect the spark plug.

   Refer to INSPECTION

3. Is there any malfunction?

   Result

   Result	Proceed to
   Specific plug is wet or covered with carbon:	Yes (A)
   Specific plug looks grayish white:	Yes (B)
   All plugs are wet or covered with carbon:	Yes (C)
   All plugs look grayish white:	Yes (D)
   -	No

Result:  5

No 

SYMPTOM TROUBLESHOOTING COMPLETED. 

Result:  1

Yes (A) 

See step  18

Result:  2

Yes (B) 

See step  19

Result:  3

Yes (C) 

See step  20

Result:  4

Yes (D) 

See step  21

1. Are the spark plugs wet/covered with carbon from the engine oil?

   Result

   Result
   Yes
   No

Result:  2

Yes 

INSPECT ALL AREAS RELATED TO OIL, WORKING UP AND DOWN. 

1. Inspect all areas related to oil, working up and down.
2. Repair or replace the malfunctioning part according to the inspection results.

Result:  1

No 

See step  3

1. Inspect the spark plugs for the following:
   1. Air gap
   2. Cracked insulator
   3. Heat range
   4. Worn electrode
2. Is there any malfunction?

   Result

   Result
   Yes
   No

Result:  2

Yes 

REPLACE THE SPARK PLUG. 

1. Refer to REMOVAL

Result:  1

No 

See step  4

1. Measure the compression pressure for each cylinder.

   Refer to INSPECTION

2. Are compression pressures within specification?

   Result

   Result
   Yes
   No

Result:  2

No 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

Yes 

See step  5

1. Reinstall all spark plugs.

   Refer to INSTALLATION

2. Perform the Spark Test at the suspected cylinder.

   Refer to ON-VEHICLE INSPECTION

3. Is a strong blue spark visible (compare with normal cylinder)?

   Result

   Result
   Yes
   No

Result:  2

No 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

Yes 

See step  6

1. Inspect the fuel line pressure.

   Refer to ON-VEHICLE INSPECTION

2. Is the low side fuel pressure within specification?

   Specification

   405-485 kPa {4.13-4.94 kgf/cm² , 58.8-70.3 psi}

   Result

   Result	Proceed to
   -	Yes
   Zero or low:	No (A)
   High:	No (B)

Result:  3

No (B) 

HIGH: 

1. Replace the fuel pump unit. (Pressure regulator malfunction)

   Refer to REMOVAL

Result:  1

No (A) 

ZERO OR LOW: 

1. Inspect the fuel pump relay and the fuel pump circuit.

   Refer to INSPECTION

2. Inspect the fuel line for restriction.
   • If there is any malfunction:
     • Repair or replace the malfunctioning part according to the inspection results.
   • If there is no malfunction:
     • Replace the fuel pump unit. (Pressure regulator or fuel pump malfunction)

       Refer to REMOVAL

Result:  2

Yes 

INSPECT THE FUEL INJECTOR FOR THE FOLLOWING: 

1. Inspect the fuel injector for the following:
   1. Injection volume
   2. Leakage
   3. Open or short circuit in fuel injector
2. Repair or replace the malfunctioning part according to the inspection results.

1. Inspect the spark plug for the following:
   1. Air gap
   2. Heat range
2. Is there any malfunction?

   Result

   Result
   Yes
   No

Result:  2

Yes 

REPLACE THE SPARK PLUG. 

1. Refer to REMOVAL

Result:  1

No 

See step  8

1. Perform the Fuel Injector Operation Inspection.

   Refer to ON-VEHICLE INSPECTION

2. Do the fuel injectors operate properly?

   Result

   Result
   Yes
   No

Result:  2

No 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

Yes 

See step  9

1. Is the air cleaner element clean?

   Result

   Result
   Yes
   No

Result:  2

No 

REPLACE THE AIR CLEANER ELEMENT. 

Result:  1

Yes 

See step  10

1. Access the following PIDs using the Techstream:

   Refer to ON-BOARD DIAGNOSTIC TEST

   1. Engine coolant temperature
   2. Mass Air Flow
   3. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 1) (When engine can be started)
   4. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 2) (When engine can be started)
2. Are the PIDs normal?

   Refer to INSPECTION

   Result

   Result
   Yes
   No

Result:  2

No 

ENGINE COOLANT TEMPERATURE PID IS NOT AS SPECIFIED: 

1. Engine coolant temperature PID is not as specified:
   1. Inspect for an intermittent open circuit of the ECT sensor No. 1 and the related wiring harness.

      Refer to INSPECTION

2. Mass Air Flow PID is not as specified:
   1. Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness.

      Refer to INSPECTION

3. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 1) PID is not as specified:
   1. Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness.

      Refer to INSPECTION

4. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 2) PID is not as specified:
   1. Inspect for an intermittent open circuit of the HO2S and the related wiring harness.

      Refer to INSPECTION

5. Repair or replace the malfunctioning part according to the inspection results.

Result:  1

Yes 

See step  11

1. Perform the Purge Control System Inspection when the engine can be started.

   Refer to ON-VEHICLE INSPECTION

2. Is there any malfunction?

   Result

   Result
   Yes
   No

Result:  2

Yes 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

No 

See step  12

1. Perform the Spark Test.

   Refer to ON-VEHICLE INSPECTION

2. Is a strong blue spark visible at each cylinder?

   Result

   Result
   Yes
   No

Result:  2

No 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

Yes 

See step  13

1. Measure the compression pressure for each cylinder.

   Refer to INSPECTION

2. Are compression pressures within specification?

   Result

   Result
   Yes
   No

Result:  2

No 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

Yes 

See step  14

1. Inspect the fuel line pressure.

   Refer to ON-VEHICLE INSPECTION

2. Is the low side fuel pressure within specification?

   Specification

   405-485 kPa {4.13-4.94 kgf/cm² , 58.8-70.3 psi}

   Result

   Result
   Yes
   No

Result:  1

No 

ZERO OR LOW: 

1. Zero or low:
   1. Inspect the fuel pump relay and the fuel pump circuit.

      Refer to INSPECTION

   2. Inspect the fuel line for restriction.
      • If there is any malfunction:
        • Repair or replace the malfunctioning part according to the inspection results.
      • If there is no malfunction:
        • Replace the fuel pump unit. (Pressure regulator or fuel pump malfunction)

          Refer to REMOVAL

2. High:
   1. Replace the fuel pump unit. (Pressure regulator malfunction)

      Refer to REMOVAL

Result:  2

Yes 

VISUALLY INSPECT FOR DEFORMED EXHAUST SYSTEM PARTS. 

1. Visually inspect for deformed exhaust system parts.
2. Repair or replace the malfunctioning part according to the inspection results.

1. Access the following PIDs using the Techstream:

   Refer to ON-BOARD DIAGNOSTIC TEST

   1. Engine coolant temperature
   2. Mass Air Flow
   3. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 1) (When engine can be started)
   4. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 2) (When engine can be started)
2. Are the PIDs normal?

   Refer to INSPECTION

   Result

   Result
   Yes
   No

Result:  2

No 

PID IS NOT AS SPECIFIED: 

1. Engine coolant temperature PID is not as specified:
   1. Inspect for an intermittent open circuit of the ECT sensor No. 1 and the related wiring harness.

      Refer to INSPECTION

2. Mass Air Flow PID is not as specified:
   1. Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness.

      Refer to INSPECTION

3. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 1) PID is not as specified:
   1. Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness.

      Refer to INSPECTION

4. Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 2) PID is not as specified:
   1. Inspect for an intermittent open circuit of the HO2S and the related wiring harness.

      Refer to INSPECTION

5. Repair or replace the malfunctioning part according to the inspection results.

Result:  1

Yes 

See step  16

1. If the engine cannot be started:
   1. Inspect the intake air system for air leakage.
2. If the engine can be started:
   1. Perform the Intake Manifold Vacuum Inspection.

      Refer to ON-VEHICLE INSPECTION

3. Is air being sucked in from intake air system?

   Result

   Result
   Yes
   No

Result:  2

Yes 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

No 

See step  17

1. Inspect the fuel line pressure.

   Refer to ON-VEHICLE INSPECTION

2. Is the low side fuel pressure within specification?

   Specification

   405-485 kPa {4.13-4.94 kgf/cm² , 58.8-70.3 psi}

   Result

   Result
   Yes
   No

Result:  1

No 

ZERO OR LOW: 

1. Zero or low:
   1. Inspect the fuel pump relay and the fuel pump circuit.

      Refer to INSPECTION

   2. Inspect the fuel line for restriction.
      • If there is any malfunction:
        • Repair or replace the malfunctioning part according to the inspection results.
      • If there is no malfunction:
        • Replace the fuel pump unit. (Pressure regulator or fuel pump malfunction)

          Refer to REMOVAL

2. High:
   1. Replace the fuel pump unit. (Pressure regulator malfunction)

      Refer to REMOVAL

Result:  2

Yes 

INSPECT THE ECM GROUND CONDITION. 

1. Inspect the ECM ground condition.
2. Repair or replace the malfunctioning part according to the inspection results.

1. Go to the next step.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  2

1. Go to the next step.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  7

1. Go to the next step.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  9

1. Go to the next step.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  15