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

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)

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 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"

Has 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

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 pulg hole

Crank the engine with widely opend throttle valve and check compression pressure at each cylinder

Is compression pressure for each cylinder displayed within specifications ?

YES

▶ Go to "Check Timing " as 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

Ignition "OFF"

Check that Cam, Crank and Oil pump sprocket timing marks are correctly in alignment

Monitor these signal waveforms 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

Refer to "Fuel pressure test" in "Fuel delivery system"

Are the measured fuel pressure within specifications ?

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 as necessary above and then, go to " Verification of Vehicle Repair"procedure.