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: 1.0 - 1.1 mm (0.0394 - 0.0433 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 next 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. BPS a compression pressure gauge into spark plug hole.
7. Check compression pressure at each cylinder.

   Compression pressure  : Approx. 1, 275 kPa (13.0 kgf/cm² , 185 psi)

   Minimum pressure  : Approx. 1, 128kPa (11.5kgf/cm² , 163.6 psi)

   Difference between each cylinder  : Approx. 100 kPa (1.0 kgf/cm² , 14.5 psi)

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

   YES 

   • Go to next 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 compression on each cylinder is not the same or not similar; a burnt or defective valve seat, worn head gasket and pressure rings can be the cause of vibration of engine.

■ Ignition system check 

1. Ignition "OFF".
2. Disconnect ignition coil harness connectors from the ignition coils.
3. Do visual inspection.
   • Check contamination or damage on the ignition coils.
4. Ignition "ON" & Engine "OFF".
5. Measure the voltage between power terminal of ignition coil #1, #2, #3, #4, 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 - Engine Idle After Warm Up

   Courtesy of KIA MOTORS AMERICA, INC.

   Primary Ignition Max 4.77V

   CH. AUX - Primary Ignition Current MAX 617mA

8. Is the measured waveform within specification?

   YES 

   • Go to next 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) 

1. Ignition "OFF".
2. Connect VMI to KDS/GDS and select "Oscilloscope".
3. Connect CH A (+) probe to Control terminal (Pin No. 1) of Injector harness connector.
4. Connect AUX probe to Control terminal (Pin No. 1) of injector harness connector.
5. Warm up the engine to normal operating temperature.

   Specification  : Refer to Signal Waveform & Data below.

   Fig 2: Screen Display - Engine Idle After Warm Up

   Courtesy of KIA MOTORS AMERICA, INC.
   1. Fuel injection time - Approx 2.1ms

      CH. A - Injector Max 51.3V

      CH. AUX - Injector Current MAX 851 mA

6. Is the measured waveform 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.