System Inspection

Check power balance
NOTE: This test is used to find out if a possible cause of the problem is an error in a specific cylinder or fuel system.
Warm up the engine to normal operating temperature in order to achieve a reliable result.

CAUTION: Pull up on the parking brake and shift the gear into "P" position before the test.
1. Warm up the engine and maintain an idle state.
2. Using GDS, select engine rpm parameter in sensor display window and injector in actuation test window as seen in the figure below.
3. Press the "Start" button in the actuation test window, and when the injector stops working, record the engine rpm.
4. Repeat the test above on all cylinders.
  Specification: The deviation of the engine rpm between each cylinder should be same.
  
  Fig 1: Scantool Display - Actual Engine Speed Current Data
  Courtesy of KIA MOTORS AMERICA, INC.
  
  Fig 2: Scantool Display - Ignition Coil Enable/Disable Actuation Test
  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 the injector stops working, the problem might be due to a fuel or ignition system error.
  - If engine rpm drops over 200rpm during the power balance test, check for internal engine damage by testing compression pressure with a pressure gauge.
Check air leakage
1. Visually/physically inspect for air leakage in the intake/exhaust system, focusing on the 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 areas above?
  YES
  - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure
  NO
  - Go to the next procedure.
3. Check for air leakage in purge system
  - Remove vacuum hose between canister purge valve and intake manifold.
  - Apply an approx. 15inch HG vacuum to the removed hose after blocking one side.
  - Is vacuum maintained?
    YES
    - Go to the next procedure.
    NO
    - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure

Check fuel pressure

NOTE: Gasoline or gasoline vapors are highly flammable/explosive and an empty fuel tank can still contain explosive vapors. A fire could occur if an ignition source is present. When working on fuel system make sure that the work area has adequate ventilation. Do not smoke. Keep sparks and open flames away at all times.
The fuel system remains under pressure when the engine is not running. Release fuel system pressure before disconnecting any fuel line to reduce the chance of personal injury or fire damage to vehicle components.

IG "OFF". Disconnect fuel pump relay in junction box.
Start the engine, and wait until it stops running.
IG "OFF". Connect Fuel Pump Relay.
Install the low fuel pressure gauge to the delivery pipe using the fuel pressure gauge adaptor.
Activate the fuel pump, and with fuel pressure applied, check that there is no fuel leakage from the pressure gauge or connection part.
Measure the fuel pressure at idle.
Specification: 400 ~ 600 kPa (4.07 ~ 6.12 kg/cm² , 58 ~ 87 psi)

Is the measured fuel pressure within specifications?

YES

Go to the next procedure.

Repair or replace according to the chart below. 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 in-tank 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
    - Check for plug gap: 1.0 ~ 1.1 mm
    - Loose contact of electrical wires
    - Poor connection
  2. Measure resistance of spark plug component.
    Specification: 3 ~ 7.5k Ω
  3. Measure resistance of primary and secondary ignition coil.
    Specification : Primary ignition coil.: 0.62 ± 10% (20°C (68°F)), Secondary ignition coil: 7.0k ± 15% (20°C (68°F))
  4. Has a problem been found?
    YES
    - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure
    NO
    - Go to the next procedure.