System Inspection

Check Power Balance
NOTE: This test is to find out that possible cause of the problem is error in specific cylinder or fuel system.
Warm up the engine to normal operating temperature for getting a reliable result.

CAUTION: Pull up the parking brake and shift the gear into "P" position before the test.
1. Warm up the engine and maintain idle state.
2. Using GDS, select engine RPM parameter in sensor display window and injector in actuation test window together as follows.
3. Record engine RPM at a time when injector stops working after press "Start" button in actuation test window.
4. Repeat above test on all cylinders.
  Specification: The deviation of the engine RPM between each cylinder should be same.
  
  Fig 1: Injector Disable Cylinders Actuation Test Screen
  Courtesy of KIA MOTORS AMERICA, INC.
5. Does each cylinder show the similar engine RPM?
  YES
  - Go to next procedure.
  NO
  - If there is no change in engine RPM when injector stops working, it might be caused by fuel or ignition system error.
    NOTE: If engine RPM drops over 200rpm in power balance test, check engine internal damage by testing compression pressure with pressure gauge.
Check Air Leakage
1. Visually/physically inspect the air leakage in intake/exhaust system as following items,
  - Vacuum hoses for splits, kinks and improper connections.
  - Throttle body gasket.
  - Gasket between intake manifold and cylinder head.
  - Seals between intake manifold and fuel injectors.
2. Has a problem been found in any of the above areas?
  YES
  - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NO
  - Go to next procedure.
3. Check for air leakage in purge system.
  - Remove vacuum hose between canister purge valve and intake manifold.
  - Apply approx. 15inch HG vacuum to removed hose after blocking the one side.
  - Is vacuum maintained?
  YES
  - Go to next procedure.
  NO
  - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check Fuel Pressure

Check water or foreign substance in fuel.
Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor.
Measure the fuel pressure at idle.
Specification: 3.45 ~3.55 kg/mm²

Is the measured fuel pressure within specifications?

YES

Go to next procedure.

Repair or replace according to the table below. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Condition	Possible Cause
Fuel Pressure is too low	Fuel filter, fuel pressure regulator, in-tank fuel hose or the fuel pump
Fuel Pressure is too high	Fuel pressure regulator, hose or pipe

Check Spark Plug
1. Check spark plug and ignition coil
  1. Visually/physically inspect the following items:
    - Damaged insulation, Worn electrodes, Oil or fuel fouled, Loose terminals and cracks
    - Loose contact of electrical wires
    - Poor connection
  2. Measure resistance of spark plug component.
    Specification: 5.6 k Ω ± 20%
  3. Measure resistance of primary and secondary ignition coil.
    Specification:
    
    Primary ignition coil.: 0.56 ~ 0.68 Ω(20°C)
    
    Secondary ignition coil: 6 ~ 8 kΩ(20°C)
  4. Has a problem been found?
    YES
    - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
    NO
    - Go to next procedure.
2. Check Spark Plug
  1. 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
  2. Has a problem been found?
    YES
    - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
    NO
    - Go to next procedure.