Honda Acura NSX 1991 Service Manual page 1082

Ignition System
Spark Plug Inspection
Inspect the electrodes and ceramic insulator for:
1 .
Worm or deformed
electrodes \
Damage
gasket
Cracked
insulator
Burned or worn electrodes may be caused by:
Advanced ignition timing
l
Loose spark plug
l
range too low
Plug heat
l
Insufficient cooling
l
Fouled plug may be caused by:
Retarded ignition timing
l
Oil in combustion chamber
l
Incorrect spark plug gap
l
Plug heat range too high
l
Excessive idling/low speed running
l
Clogged air cleaner element
l
Deteriorated ignition coil
l
2. If the electrode is contaminated with accumulated
objects or dirt, clean the electrode using the plug
cleaner.
CAUTION: The plug cleaner should be used with the
air pressure of lees then 6 kg/cm*
less than 20 seconds.
23-96
3.
Improper gap
l
Oil-fouling
l
. Carbon
deposits
Cracked center
l
electrode insulator
I
Spark plug:
4.
5.
PSI)
and for
Replace the plug if the center electrode is rounded
as shown below:
NOTE: Do not use spark plugs other than those list-
ed below, because these plugs are a new type (IS0
standard).
These marks are sealed
air cleaner cover.
For all normal driving
For hot climates or contin-
Make sure that the 1.3 mm (0.051 in.) plug gauge
does not go into the gap for the platinum tip plug.
If the gauge goes into the gap, do not attempt to ad-
just but replace the plug with new bne.
Electrode Gap: 1 .I mm (0.043 in.1
Platinum tip plug:
Check and confirm that the
1.3 mm (0.051 in) plug
gauge does not go into the
Screw the plugs into the cylinder head finger tight,
then torque them to 18 N-m (I .8 kg-m, 13 lb-ft).
on the