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?

	▶ Repair or replace as necessary. Go to "Verification of Vehicle Repair" procedure
	▶ 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 exhaust manifold and Three way catalyst for air leakage.

Has a problem been found in any of the above areas?

	▶ Repair or replace as necessary. Go to "Verification of Vehicle Repair" procedure
	▶ Go to "Check for air leakage in Positive Crankcase Ventilation Valve(PCV)

Remove PCV valve from cylinder head cover by pulling 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?

	▶ Repair or replace as necessary. Go to "Verification of Vehicle Repair" procedure
	▶ 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 plug hole.

Crank the engine with throttle valve wide open and check compression pressure at each cylinder.

Is compression pressure for each cylinder displayed within specifications ?

▶ Go to "Check Timing " as below.

▶ 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 head gasket. Repair as necessary. Go to "Verification of Vehicle Repair" procedure

IG "OFF"

Monitor these signal waveforms from CAM and Crankshaft position Sensor are correctly aligned.

Reference: The 17th CKP signal after the missing tooth is aligned with the high voltage CMP signal.

Are all timing marks aligned correctly?

	▶ Go to "Check Fuel Pressure " as below
	▶ Check that Cam, Crank and Oil pump sprocket timing marks are correctly aligned. Repair or readjust as necessary. Go to "Verification of Vehicle Repair" procedure

IG "OFF". Disconnect Fuel Pump Relay in Junction Box.

Start engine and wait until it stalls.

IG "OFF". Connect Fuel Pump Relay.

Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor. (Refer to Shop Manual)

Activate the fuel pump, check that there are no fuel leaks from the pressure gauge or fuel system.

Measure the fuel pressure at idle.

Is the measured fuel pressure within specifications ?

	▶ 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.
	▶ Repair or replace according to the table below. Go to " Verification of Vehicle Repair" procedure.