System Inspection

■ Check power balance 

Reference 

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.

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 follow figure.
3. Recode 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: Scan Tool Actuation Test Injector - Cylinder 1, No Results

   Courtesy of HYUNDAI MOTOR CO.
   Fig 2: Scan Tool Actuation Test Injector - Cylinder 1, Success

   Courtesy of HYUNDAI MOTOR CO.
5. Does each cylinder show the similar engine rpm?

   Specification 

   ■ Go to next precedure.

   CAUTION: ■ If there is no change in engine rpm when injector stops working, it might be caused by fuel or ignition system error.

   Reference 

   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 precedure.
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 precedure.

   NO 

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

   ■ Check fuel pressure 

   1. Check water or foreign substance in fuel
   2. Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor.
   3. Measure the fuel pressure at idle.

      Specification:  3.45 ~3.55 kg/mm

   4. Is the measured fuel pressure within specifications ?

      YES 

      • Go to next precedure.

      NO 

      • Repair or replace according to the below table. And then, go to Verification of Vehicle Repair  procedure.
        FUEL PRESSURE CONDITION
        
        

        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 connect of electrical wires

            - Poor connection

         2. Measure resistance of spark plug component.

            Specification:  5.6 k ? ± 20%

         3. Measure resistance of primary and secondary ignition coil.

            Specification: 

            Primary ignition coil. : 0.56 ~ 0.68 ?(20°C)

            Secondary ignition coil : 6 ~ 8 k?(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 precedure.
      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 precedure.