Distributor; Ignition Coil - Jeep Wrangler 1999 Electronic Service Manual

TJ
REMOVAL AND INSTALLATION (Continued)
Fig. 22 Cable Removal
(2) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert.
(4) Inspect the spark plug condition. Refer to
Spark Plugs in the Diagnostics/Service Procedures
section of this group.
PLUG CLEANING
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After clean-
ing, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will
remain on the spark plug insulator and will cause
plug misfire.
PLUG GAP ADJUSTMENT
Check the spark plug gap with a gap gauge tool. If
the gap is not correct, adjust it by bending the
ground electrode (Fig. 23). Never attempt to adjust
the gap by bending the center electrode.
SPARK PLUG GAP
• 2.5L 4-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
• 4.0L 6-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
PLUG INSTALLATION
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion. This may result
in a change in the spark plug gap, or a cracked por-
celain insulator.
Fig. 23 Setting Spark Plug Gap—Typical
When replacing the spark plug and ignition coil
cables, route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise. It could cause cross ignition of the spark plugs,
or short circuit the cables to ground.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading.
(2) Tighten the spark plugs to 35-41 N·m (26-30 ft.
lbs.) torque.
(3) Install spark plug cables over spark plugs.

IGNITION COIL

The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
REMOVAL
On the 2.5L 4-cylinder engine, the ignition coil is
mounted to a bracket on side of engine (to rear of
distributor) (Fig. 24).
On the 4.0L 6-cylinder engine, the ignition coil is
mounted to a bracket on side of engine (to front of
distributor) (Fig. 25).
(1) Disconnect ignition coil secondary cable from
ignition coil.
(2) Disconnect engine harness connector from igni-
tion coil.
(3) Remove ignition coil mounting bolts (nuts are
used on back side of bracket on some coils).
(4) Remove coil from vehicle.
IGNITION SYSTEM 8D - 11