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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSHYUNDAI1991SONATA V6-3.0LREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTIGNITION SYSTEMSPARK PLUGTESTING AND INSPECTION
1991 Hyundai Sonata V6-3.0L
Spark Plug: Testing and Inspection
1991 Hyundai Sonata V6-3.0LSECTION Testing and Inspection
INSPECTION OF SPARK PLUGS
1. Disconnect spark plug cable from the spark plug. If the spark plug cable is removed by pulling on the cable, it may be damaged.
2. Using a plug wrench, remove all plugs from cylinder head.
CAUTION: Use care not to allow foreign matter to enter through plug holes.
3. Check the spark plugs for the following:
Broken insulator
Worn electrode
Carbon deposits
Damaged or broken gasket
Burnt condition of porcelain insulator at spark gap.
NOTE: Dark deposits indicate too rich a fuel mixture, light (white) deposits indicate too lean a fuel mixture, advanced ignition timing or insufficient plug tightening
4. Check plug gap using a plug gap gauge and adjust if necessary.
Standard value: 1.0-1.1mm (0.039-0.043in.)
5. Tighten spark plug to specified torque. If overtorqueing occurs, damage to threaded portion of cylinder head might result.
Spark plug torque: 20-30Nm (204-306 kg.cm, 15-21 lb.ft)
INSPECTION OF SPARK PLUG CABLES
1. Check end caps and outer shell for cracks.
2. Measure resistance.
Standard value:
Coil lead.................Approx. 2.7kohm
Spark plug cable No.1......Approx. 10.6kohm
Spark plug cable No.2......Approx. 13.1kohm
Spark plug cable No.3......Approx. 16.7kohm
Spark plug cable No.4......Approx. 22.1kohm
1. Disconnect spark plug cable from the spark plug. If the spark plug cable is removed by pulling on the cable, it may be damaged.
2. Using a plug wrench, remove all plugs from cylinder head.
CAUTION: Use care not to allow foreign matter to enter through plug holes.
3. Check the spark plugs for the following:
Broken insulator
Worn electrode
Carbon deposits
Damaged or broken gasket
Burnt condition of porcelain insulator at spark gap.
NOTE: Dark deposits indicate too rich a fuel mixture, light (white) deposits indicate too lean a fuel mixture, advanced ignition timing or insufficient plug tightening
4. Check plug gap using a plug gap gauge and adjust if necessary.
Standard value: 1.0-1.1mm (0.039-0.043in.)
5. Tighten spark plug to specified torque. If overtorqueing occurs, damage to threaded portion of cylinder head might result.
Spark plug torque: 20-30Nm (204-306 kg.cm, 15-21 lb.ft)
INSPECTION OF SPARK PLUG CABLES
1. Check end caps and outer shell for cracks.
2. Measure resistance.
Standard value:
Coil lead.................Approx. 2.7kohm
Spark plug cable No.1......Approx. 10.6kohm
Spark plug cable No.2......Approx. 13.1kohm
Spark plug cable No.3......Approx. 16.7kohm
Spark plug cable No.4......Approx. 22.1kohm
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.