G424F(FE) Service Manual Chapter 4. Engine Electrical System 105
Spark Plug Replacement
Removal
Remove or disconnect
1. Remove the spark plug wires. Refer to spark Plug
Wire Replacement.
2. Loosen each spark plug 1 or 2 turns.
3. Brush or air blast away any dirt form around the
spark plugs.
4. Remove the spark plugs 1 at a time. Place each
plug in a tray marked with the corresponding
cylinder number. See Figure 82.
5. Inspect each spark plug. See Spark Plug
Inspection
Installation
Install or connect
1. Properly position each spark plug washer.
2. Inspect each spark plug gap. Adjust each plug as
needed.
Specification
Spark plug gap: 0.8 to 0.9 mm (0.031 to 0.035 in.)
3. Head start the spark plugs in the corresponding
cylinders. See Figure 82.
CAUTION
Only use a spark plug socket or wrench to
tighten the spark plugs. Do not force the spark
plug into the cylinder head. Any misalignment
can damage the aluminum threads in the
cylinder head and may required the replacement
of the cylinder head.
4. Tighten the spark plug to 20 N•m (15 Ibf ft)
Spark Plug Inspection
Usage
1. Ensure that the correct spark plug is installed. An
incorrect spark plug causes driveability conditions.
2. Ensure that the spark plug has the correct heat
range. An incorrect heat range the following
conditions:
• Spark plug fouling – Colder plug
• Pre-ignition causing spark plug and/or engine
damage – Hotter plug
Inspect
1. Inspect the terminal post for damage.
a. Inspect for a bent or broken terminal post.
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