Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 737
6D2–5
IGNITION SYSTEM
Spark Plug
Removal
1. Remove spark plugs.
Inspection and Repair
The spark plug affects entire engine performance and
therefore its inspection is very important.
D
Check electrode and insulator for presence of cracks,
and replace if any.
D
Check spark plug gap. Replace spark plugs if
measured value is out of standard.
Spark plug gap : 1.0 – 1.1 mm (0.4 – 0.043 in)
011RS011
D
Check gasket for damage, and replace if necessary.
D
Measure insulation resistance with an ohmmeter, and
replace if faulty.
D
Check fuel and electrical systems if spark plug is
extremely dirty.
D
Use spark plugs having low heat value (hot type plug)
if fuel and electrical systems are normal.
D
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:
D
Too rich mixture
D
Presence of oil in combustion chamber
D
Incorrect spark plug gap
Burning Electrodes
This fault is characterized by scorched or heavily oxidized
electrode or blistered insulator nose.
Possible causes:
D
Too lean mixture
D
Improper heat value
Measuring Insulation Resistance
D
Measure insulation resistance using a 500 volt
megaohm meter.
D
Replace spark plugs if measured value is out of
standard.
Insulation resistance: 50 M
W
or more
011RS010
Cleaning Spark Plugs
D
Clean spark plugs with a spark plug cleaner.
D
After spark plug is thoroughly cleaned, check
insulator for presence of cracks.
D
Clean threads and metal body with a wire brush.
Installation
1. Spark plugs
D
Tighten spark plugs to the specified torque.
Torque: 18 N·m (13 lb ft)