System Inspection

■ Spark plug check 

1. Remove the spark plugs.
2. Visually/physically inspect the following items:
   • Damaged insulation, Worn electrodes, Oil or fuel fouled, Loose terminals and cracks.
   • Check for plug gap: 0.9 - 1.0 mm (0.035 - 0.039 in.)
   • Check if the spark plug for the relevant cylinder is lighter in color than the other plugs.
3. Have any problems been found?

   YES 

   • Repair or replace as necessary and go to "Verification Of Vehicle Repair " procedure.

   NO 

   • Go to "Compression pressure check" procedure.

■ Compression pressure check 

1. Warm up the engine to normal operating temperature.
2. Remove the fuel pump fuse(15A).
3. Wait until the engine stopped.
4. Remove the ignition coils and spark plugs.
5. Crank the engine to remove any foreign material in the cylinders.
6. Put a compression pressure gauge into spark plug hole.
7. Check compression pressure at each cylinder.

   Specification:  Approx. 15kg/cm²

8. Is compression pressure for each cylinder displayed within specifications?

   YES 

   • Go to "Ignition system check" procedure.

   NO 

   • Add a small amount of oil through the spark plug hole, and repeat above steps. If the addition of oil causes the compression to rise, the cause is a worn or damaged piston ring or cylinder inner surface.
   • If the compressions at each cylinders are not same or not simular, a burnt or defective valve seat, worn head gasket and pressure rings can be the cause of vibration of engine. Repair as necessary and go to "Verification Of Vehicle Repair " procedure.

■ Ignition system check 

1. IG KEY "OFF".
2. Disconnect ignition coil harness connectors from the ignition coils.
3. Do visual inspection.
   • Check contamination or damege on the ignition coils.
4. IG KEY "ON" & ENG "OFF".
5. Measure the voltage between power terminal of ignition coil #1, #2, #3, #4, #5 and #6 harness connectors and chassis ground.

   Specification:  Approx 12V

6. Connect ignition coil harness connectors to the ignition coils.
7. Compare with the below reference value and ignition primary waveform and determine whether the values are normal or not.
   Fig 1: Screen Display - Signal Waveform In Current Data At Engine Idle After Warm Up

   Courtesy of KIA MOTORS AMERICA, INC.

   Primary Ignition control time - Approx. 1965us

   CH. A - Primary Ignition Max 140V

   CH. AUX - Primary Ignition Current MAX 6.75A

8. Is measured value within specification?

   YES 

   • Go to "Check Injector performance" procedure.

   NO 

   • Carefully re-do this troubleshooting guide steps.
   • If no problems were found with the circuits or connectors, replace the Ignition Coil and go to "Verification Of Vehicle Repair " procedure.

■ Check Injector performance (#1, 2, 3, 4, 5, 6) 

1. IG KEY "OFF".
2. Connnect CH A probe to control terminal of Injector(High side) and CH B probe to control terminal of Injector(Low side).
3. Connnect CH AUX probe to control wire of Injector.
4. Warm up the engine to normal operating temperature.

   Specification:  Refer to SIGNAL WAVEFORM & DATA 

   Fig 2: Screen Display - Signal Waveform In Current Data At Engine Idle After Warm Up

   Courtesy of KIA MOTORS AMERICA, INC.
   Fig 3: Screen Display - Signal Waveform In Current Data At Acceleration

   Courtesy of KIA MOTORS AMERICA, INC.

   A: Fuel injection time - Approx 1110us

   CH. A - Injector Max 48.8V

   CH. AUX - Injector Current MAX 11.7A

   Fuel injection time - Approx. 2910us

   CH. A - Injector Max 49.3V

   CH. AUX - Injector Current MAX 11.8A

5. Does the injector operate properly within specification?

   YES 

   • Go to "Verification Of Vehicle Repair " procedure.

   NO 

   • Carefully re-do this troubleshooting guide steps.
   • If no problems were found with the circuits or connectors, replace the injector and go to "Verification Of Vehicle Repair " procedure.