Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
System Inspection
- Spark plug check
- Remove the spark plugs.
- Visually/physically inspect the following items:
- Damaged insulation, Worn electrodes, Oil or fuel fouled, Loose terminals and cracks.
- Check for plug gap: 0.9 - 1.0 mm (0.035 - 0.039 in.)
- Check if the spark plug for the relevant cylinder is lighter in color than the other plugs.
- Have any problems been found?
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.
- Remove the fuel pump fuse (15A).
- Wait until the engine stopped.
- Remove the ignition coils and spark plugs.
- Crank the engine to remove any foreign material in the cylinders.
- Put a compression pressure gauge into spark plug hole.
- Check compression pressure at each cylinder.
Specification: Approx. 15kg/cm2
- 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 compressions at each cylinders are not same or not similar, a burnt or defective valve seat, worn head gasket and pressure rings can be the cause of vibration of engine. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Ignition system check
- IG KEY "OFF".
- Disconnect ignition coil harness connectors from the ignition coils.
- Do visual inspection.
- Check contamination or damage on ignition coil.
- IG KEY "ON" & ENG "OFF"
- Measure the voltage between power terminal of ignition coil #1, #2, #3, #4 harness connector and chassis ground.
Specification: Approx 12V
- Connect ignition coil harness connectors to the ignition coils.
- Compare with the below reference value and ignition primary waveform and determine whether the values are normal or not.
Primary Ignition control time - Approx. 750us
CH. A - Primary Ignition Max 266V
CH. AUX - Primary Ignition Current MAX 10.4A
YES
- Go to "Check Injector performance" procedure.
NO
- Substitute with a known-good IG Coil and check for proper operation. If the problem is corrected, replace IG Coil and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Check Injector performance
- IG KEY "OFF".
- Connect CH A probe to control terminal of Injector (High side) and CH B probe to control terminal of Injector (Low side).
- Connect CH AUX probe to control wire of Injector.
- Warm up the engine to normal operating temperature.
Specification: Refer to SIGNAL WAVEFORM & DATA
A: Fuel injection time - Approx. 1545us
CH. A - Injector Max 64.4V
CH. AUX - Injector Current MAX 9.09A
- Does the injector operate properly within specification?
YES
- Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Substitute with a known-good Injector and check for proper operation. If the problem is corrected, replace Injector and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.