Spark Plug - Isuzu 1999 RODEO Workshop Manual

6D2–4 IGNITION SYSTEM (6VD1 3.2L)
Removal
1. Remove spark plugs.
Inspection and Repair
The spark plug affects entire engine performance and
therefore its inspection is very important.
f Check electrode and insulator for presence of cracks,
and replace if any.
f Check electrode for wear, and replace if necessary.
f Check gasket for damage, and replace if necessary.
f Measure insulation resistance with an ohmmeter, and
replace if faulty.
f Adjust spark plug gap to 1.0 mm (0.04 in) ∼ 1.1 mm
(0.043 in).
f Check fuel and electrical systems if spark plug is
extremely dirty.
f Use spark plugs having low heat value (hot type plug)
if fuel and electrical systems are normal.
f Use spark plugs having high heat value (cold type
plug) if insulator and electrode are extremely burned.
Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and
insulator of spark plug reduces the engine performance.
Possible causes:
f Too rich mixture
f Presence of oil in combustion chamber
f Incorrectly adjusted spark plug gap
Burning Electrodes
This fault is characterized by scorched or heavily oxidized
electrode or blistered insulator nose.
Possible causes:
f Too lean mixture
f Improper heat value
Measuring Insulation Resistance
f Measure insulation resistance using a 500 volt
megaohm meter.
f Replace spark plugs if measured value is out of
standard.
Insulation resistance: 50 MW or more

Spark Plug

Cleaning Spark Plugs
f Clean spark plugs with a spark plug cleaner.
f Raise the ground electrode to an angle of 45 to 60
degrees. If electrode is wet, dry it before cleaning.
f After spark plug is thoroughly cleaned, check
insulator for presence of cracks.
f Clean threads and metal body with a wire brush.
f File the electrode tip if electrode is extremely worn.
f Bend the ground electrode to adjust the spark plug
gap.
Installation
1. Spark plugs
f Tighten spark plugs to the specified torque.
Torque: 18 N·m (13 lb ft)
011RS010
011RS011