System Inspection

■ Spark Plug Inspection 

1. Remove spark plugs.
2. Visually/physically inspect the following items:
   • Damaged insulation, worn electrodes, oil or fuel fouled, loose terminals and cracks.
   • Check for spark 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 Inspection" procedure below.

■ Compression Pressure Inspection 

1. Warm up the engine to normal operating temperature.
2. Remove the fuel pump fuse (15A).
3. Wait until the engine has stopped (runs out of fuel).
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.

   Compression pressure specification: 

   Standard: 178psi (200~250 RPM)

   Minimum: 156psi

   Difference between each cylinder: 14psi or less

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

   YES 

   • Go to "Ignition System Inspection" procedure below.

   NO 

   • Add a small amount of oil through the spark plug hole, and repeat the steps above.

     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 similar, a burnt or defective valve seat, worn head gasket and/or pressure rings can be the cause of vibration of engine. Repair as necessary and go to "Verification of Vehicle Repair " procedure.

■ Ignition System Inspection 

1. Ignition "OFF".
2. Disconnect ignition coil harness connectors from the ignition coils.
3. Perform visual inspection.
   • Check contamination or damage on ignition coils.
4. Ignition "ON", Engine "OFF".
5. Measure the voltage between power terminal of ignition coils #1, #2, #3, #4 harness connector and chassis ground.

   Specification:  Approx 12V

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

   Courtesy of KIA MOTORS AMERICA, INC.

   Primary ignition control time - Approx. 750us

   CH. A - Primary ignition MAX 266V

   CH. AUX - Primary ignition current MAX 10.4A

   YES 

   • Go to "Check Injector Performance" procedure below.

   NO 

   • Substitute with a known-good ignition coil and check for proper operation. If the problem is corrected, replace ignition coil and then go to "Verification of Vehicle Repair " procedure.

■ Check Injector Performance 

1. Ignition "OFF".
2. Connect CH A probe to control terminal of injector (High Side) and CH B probe to control terminal of injector (Low Side).
3. Connect CH AUX probe to injector control wire.
4. Warm up the engine to normal operating temperature.

   Specification:  Refer to Signal Waveform & Data below

   Fig 2: Scantool Display - Signal Waveform & Data (Engine Idle After Warm-Up)

   Courtesy of KIA MOTORS AMERICA, INC.

   A: Fuel injection time - Approx. 1545us

   CH. A - Injector MAX 64.4V

   CH. AUX - Injector current MAX 9.09A

5. Does the injector operate properly within specification?

   YES 

   • Go to "Verification of Vehicle Repair " procedure.

   NO 

   • Substitute with a known-good GDI Injector and check for proper operation. If the problem is corrected, replace GDI Injector and then go to "Verification of Vehicle Repair " procedure.