Spark Plug Cable & Ignition Coil Inspection
Visually/physically inspect the spark plug cable and ignition coil related to the misfiring cylinder(s) for the following conditions.
- Damage, cracks, carbon and flashover
- Poor connection or damaged harness
- Connected to the incorrect cylinders at the ignition coil and spark plug
Measure the resistance of the spark plug cable related to the misfiring cylinder(s).
Specification : 5.6kΩ/m ±20%
Measure the resistance of the primary and secondary ignition coil related to the misfiring cylinder(s).
Condition | Temp.(℉) | Primary ignition coil (Ω) | Secondary ignition coil(㏀) |
20 | 68 | 0.56~0.68 | 6~8 |
Check Primary ignition coil Performance.
- IG KEY "OFF".
- Disconnect ignition coil harness connectors from the ignition coils.
- Do visual inspection.
▶ Check contamination or damege on the ignition coils.
- IG KEY "ON" & ENG "OFF".
- Measure the voltage between power terminal of ignition coil #1, #2, #3, #4 harness connectors 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.
Fig.1) Engine Idle after Warm Up
CH. A - Primary ignition Max 264V
CH. AUX - Primary ignition Current Max 9.32A
Was a problem found in any of the above areas?
![]() | ▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure. |
![]() | ▶ Go to next step as below. |
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?
![]() | ▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure. |
![]() | ▶ Go to next step as below. |
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. 1,470kPa (15.0kgf/cm², 213psi)
Is compression pressure for each cylinder displayed within specifications ?
![]() | ▶ Verify if the engine has excessive coolant consumption. If yes, check for damaged inlet water passage, engine block, cylinder head or head gasket. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure. |
![]() | ▶ If the cylinder compression in 1 or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat compression test for cylinders with low compression pressure. - If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged. - If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure. |