Summit L4-1795cc 1.8L SOHC (1995)
Spark Plug: Testing and Inspection
SPARK PLUG TEST
1. Remove the spark plug and connect to the spark plug cable.
2. Ground the spark plug outer electrode (body), and crank the engine. Check to be sure that there is an electrical discharge between the electrodes at
this time.
SPARK PLUG INSPECTION
1. Check the following items to see that electrodes are not burnt, and insulators are not broken, and how porcelain insulator is burnt.
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Broken insulators
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Wearing electrodes
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Deposited carbon - For cleaning, use a plug cleaner or wire brush. Clean porcelain insulator above shell as well.
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Damaged or broken gasket
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Burnt condition of porcelain insulator at spark gap. Dark deposit of carbon indicates too rich a fuel mixture or extremely low air intake. Also,
misfiring due to excessive spark gap is suspected. White burn indicates too lean a fuel mixture or excessively advanced ignition timing. Also
insufficient plug tightening is suspected.
2. Clean with a plug cleaner. Use an air gun to remove dust deposited on plug threads.
3. Check plug gap using a plug gap gauge and adjust if it is not as specified.
Standard value: 1.0 - 1.1 mm (0.039 - 0.043 in.)
