Check Spark Plug Cable
Visually/physically inspect the following items:
Damage, cracks and flashover
Measure the resistance of the spark plug cable
Specification : 5.6kΩ/m ± 20% at 20℃68℃)
Is the measured resistance within specifications ?
YES
▶ Go to "Check Spark Plug" as below.
NO
▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
Check Spark Plug
Remove cylinder’s spark plugs
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 (0.039 - 0.043 in.)
Check if the spark plug for the relevant cylinder is lighter in color than the other plugs.
Have 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 " Check Air Leakage " as below.
Check Air Leakage
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.
Exhaust system between HO2S and Three way catalyst for air leakage.
Have 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 "Check for air leakage in Positive Crankcase Ventilation Valve(PCV).
Check for air leakage in Positive Crankcase Ventilation Valve(PCV)
Remove PCV valve from cylinder head cover by puling ventilation hose.
With engine idling block PCV valve opening.
Verify that vacuum is felt.
Revmove PCV valve.
Blow through valve from prot "A" and verify that air comes out of prot "B"
Blow through valve from prot "B" and verifty that no air comes out of port "A"
Have a problem been found?
YES
▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO
▶ Go to "Check Compression pressure" as below.
Check Compression pressure
Warm up the engine to normal operationg temperature.
Disconnect the spark plug cables and remove the spark plugs.
Crank the engine to remove any foreign material in the cylinders.
Put compression pressure gauge into spark pulg hole.
Crank the engine with widely opend throttle valve and check compression pressure at each cylinder.
Specification : 1,200kPa(12.2 kg/cm²,170 psi)
Is compression pressure for each cylinder displayed within specifications ?
YES
▶ Go to "Check Timing belt deflection .
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 remains the same, the cause is a burnt or defective valve seat, or pressure is leaking from the gasket.
Repair as necessary and go to "Verification vehicle Repair" procedure.
Check Timing belt deflection
Check timing belt deflection and deflection pressure.
Specification : Deflection : 0.2 ~ 0.27 in. (5.0 ~ 7.0mm)
Is the timing belt deflection within the specifications ?
YES
▶ Go to "Check Timing" as below.
NO
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check Timing
Ignition "OFF"
Check that Cam, Crank and Oil pump sprocket timing marks are correctly in alignment.
Engine "ON" & Monitor signalwaveform from CAM and Crank shaft position Sensor are correctly in alignment.
Are all timing marks alligned correctly ?
YES
▶ Go to "Check Fuel Pressure Test" as below.
NO
▶ Repair or readjust as necessary and go to "Verification of Vehicle Repair" procedure.
Fuel Pressure Test
1.Be cautious that Fuel is explosive and an empty fuel tank can still contain explosive gases.When working on fuel system make sure to supply adequate ventilation to the work area. Do not smoke, and keep sparks and open flames away.
2.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 presonal injury or fire damage to vehicle components.Be cautious that Fuel is explosive and an empty fuel tank can still contain explosive gases.
Check the fuel for excessive water, alcohol, or other contaminants. Replace contaminated fuel as necessary.
Install the fuel pressure gauge to the fuel pressure gauge adaptor.
Apply battery voltage to the terminal for the pump drive and activate the fuel pump: then, with fuel pressure applied, check that there is no fuel leakage from the pressure gauge or connection part.
Disconnect the vacuum hose from the pressure regulator, and plug the hose end.Measure the fuel pressure at idle.
Specification : 320~340kPa(3.26~3.47 kg/㎠, 46~49 psi)
Measure the fuel presure when the vacuum hose is connectoed to the pressure regulator.
Specification : Approx. 255kPa(2.57 kg/㎠, 37 psi)
Are the measured fuel pressure within specifications ?
YES
▶ Go to "Check injector leakage" as below.
NO
▶ Repair or replace according to the below table. 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 |
No different fuel pressure when vacuum hose is connected or not | The vacuum hose or the nipple |
Check Injector clog
Ignition " OFF " after checking the Fuel Pressure Test.
Stop the engine and check for a change in the fuel pressure gauge reading for 5 minutes.
Does fuel pressure retain after engine is stopped ?
YES
▶ Substitute with a known - good PCM and check for proper operation.
▶ If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
NO
▶ Repair or replace according to the below table. And then, go to " Verification of Vehicle Repair" procedure.
Condition | Possible Cause |
Fuel Pressure reading drops slowly after engine is stopped | Injector leakage |
Fuel Pressure reading drops immediately after engine is stopped | Fuel pump |
