System Inspection
- 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.
- 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 "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
- 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 "Check For Air Leakage In Positive Crankcase Ventilation Valve (PCV) " as follows.
- Visually/physically inspect the air leakage in intake/exhaust system as following items,
- 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.
- Remove PCV valve.
- Blow through valve from port "A" and verify that air comes out of port "B".
- Blow through valve from port "B" and verify that no air comes out of port "A".
- 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 "Check Compression Pressure " as follows.
- Check Compression Pressure
- Warm up the engine to normal operating 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 Plug hole.
- Crank the engine with widely opened throttle valve and check compression pressure at each cylinder.
Specification: 1323kPa (13.5 kg/cm2 , 192 psi)
- Is compression pressure for each cylinder displayed within specifications?
YES
Go to "Check Timing " procedure below.
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 OF VEHICLE REPAIR " procedure
- Check Timing
- IG "OFF"
- Monitor these signal waveforms from CAM and Crank shaft position Sensor are correctly aligned.
- Are all timing marks aligned correctly?
YES
Go to "Check Fuel Pressure " procedure below.
NO
Check that Cam, Crank and Oil pump sprocket timing marks are correctly aligned. Repair or readjust as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Check Fuel Pressure NOTE:
- 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.
- 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" and disconnect Fuel Pump Relay in Junction Box.
- Start-up and wait until it stops itself.
- IG "OFF" and connect Fuel Pump Relay.
- Install the fuel pressure gauge to the delivery pipe with 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: 374.6 ~ 384.4 kPa (3.82 ~ 3.92 kg/cm2 , 54.3 ~ 55.8 psi)
- Is the measured fuel pressure within specifications?
YES
Substitute with a known - good ECM and check for proper operation. If the problem is corrected, replace ECM 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 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