Viper V10-488 8.0L (1992)
Spark Plug: Testing and Inspection
Broken, Cracked or Chipped Insulator
Spark Plug Inspection
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A chipped electrode insulator usually results from bending the center electrode while adjusting the spark plug electrode gap.
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Under certain conditions, severe detonation can also separate the insulator from the center electrode. Spark plugs with this condition must be
replaced.
Brown to Gray/Tan Color - Normal Operating Condition
Spark Plug Inspection
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The few deposits present will be probably light tan or slightly gray in color with most grades of commercial gasoline. There will not be evidence
of electrode burning. Gap growth will not average more than approximately 0.025 mm (0.001 in) per 1,600 km (1,000 miles) of operation. Spark
plugs that have normal wear can usually be cleaned, have the electrodes filed and gapped, and then be installed.
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Some fuel refiners in several areas of the United States have introduced a manganese additive (MMT) for unleaded fuel. During combustion, fuel
with MMT causes the entire tip of the spark plug to be coated with a rust colored deposit. This rust color can be misdiagnosed as being caused by
coolant in the combustion chamber. Spark plug performance is not affected by MMT deposits.
Dry, Fluffy Black Deposits - Cold or Carbon Fouling
DESCRIPTION:
Dry, fluffy black deposits
POSSIBLE CAUSE
ACTION
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Poor Ignition Output
- Check distributor to coil connections.
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Electrode Gap Bridging
