Spark plug check
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 "Compression pressure check" procedure.
Compression pressure check
Warm up the engine to normal operating temperature.
Disconnect the spark plug cables. And remove the spark plugs and fuel pump relay.
Crank the engine to remove any foreign material in the cylinders.
Put compression pressure gauge into spark pulg hole.
Check compression pressure at each cylinder.
Specification : Approx. 15kg/㎠
Is compression pressure for each cylinder displayed within specifications ?
YES
Go to "Ignition system check" procedure.
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 system check
Key "OFF".
Disconnect Ignition coil connector.
Do visual inspection.
▶ Check contamination or damege on ignition coil.
Key "ON".
Measure the voltage between terminal 2 of ignition coil #1, #2, #3, #4 harness connector and chassis ground.
Specification : Approx. B+
Is the measured voltage within specifications ?
YES
Go to "Ignition coil check" procedure.
NO
Repair Open or Short to ground in power circuit, and go to "Verification of Vehicle Repair" procedure.
Ignition coil check
Measure the resistance between terminal 1 and 2 of ingnition coil connector #1, #2, #3, #4.
(Component side / Primary coil)
Specification :
Ignition Coil Resistance (Primary) |
0.71 ± 0.11 Ω at 20 ℃ (68℉) |
Is the measured resistance within specifications ?
YES
Go to "Timing mark check" procedure.
NO
Substitute with a known - good ignition coil and check for proper operation.
If the problem is corrected, replace ignition coil and go to "Verification of Vehicle Repair" procedure.
Timing mark check
Key "OFF".
Check the timing mark.
Specification :
Is the timing mark normal?
YES
Go to "Air leakage check" procedure.
NO
Repair and go to "Verification of Vehicle Repair" procedure.
Air leakage check
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 "PCV(Positive Crankcase Ventilation) valve check" procedure.
PCV(Positive Crankcase Ventilation) valve check
Key "OFF".
Disconnect PCV valve.
Check the movement of plunger by putting in and out a thin stick.
Is the movement of plunger normal?
YES
Go to "Injector check" procedure.
NO
Substitute with a known - good PCV valve and check for proper operation.
If the problem is corrected, replace PCV valve and go to "Verification of Vehicle Repair" procedure.
Injector check
Key "OFF".
Remove injectors.
Check leakage or clog on injectors.
Measure the resistance between terminal 1 and 2. (Component side)
Specification :
Temperature[℃] | Resistance[Ω] |
20 | 14.5±0.7 |
Is the measured resistance within specification ?
YES
Go to "Fuel line check" procedure.
NO
Substitute with a known - good injector and check for proper operation.
If the problem is corrected, replace injector and go to "Verification of Vehicle Repair" procedure.
Fuel line check
Check clog, contamination and damage on fuel line.
- Splits, kinks and improper connections of fuel line pipe.
- Interference, damage and improper connections of vacuum hose on fuel line.
- Improper connection of connectors on fuel line.
Is the fuel line normal?
YES
Go to "Fuel pressure check" procedure.
NO
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Fuel pressure check
Key "OFF".
Disconnect a fuel pump relay.
Engine start and wait until engine stop. and then key "OFF".
Install fuel pump relay.
Connect fuel pressure guage using the correct adaptor.
Start the engine , and record fuel pressure.
Specification : Approx. 3.5㎏/㎠
Is the fuel pressure normal?
YES
Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage. So, check poor connections and the related circuit between ECM and component thoroughly. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Check clogging on the fuel filter.
Check the fuel supply and return line.
Repair as necessary and go to "Verification of vehicle Repair" procedure.