REMOVAL AND INSTALLATION
SPARK PLUG CABLE SERVICEÐ2.4L
The cables insulate the spark plugs and covers the
top of the spark plug tube (Fig. 6). To remove the
cables, lightly grasp the top of the cable. Rotate the
insulator 90É and pull straight up. To replace the
cables, disconnect the cable from the ignition coil.
Ensure the #1 and #4 cables run under the #2
and #3 ignition coil towers. Keep #4 cable away
from the oil fill cap.
SPARK PLUG SERVICE
When replacing the spark plugs and spark plug
cables, route the cables correctly and secure them inthe appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise, cross ignition of the spark plugs orshort cir-
cuit the cables to ground.
Never Wire Brush Spark Plugs.The spark plug
insulator tip is harder than the bristles of wire
brushes. Bristles of wire brushes can leave a conduc-
tive, metallic film on the insulator which could lead
to conductive deposits. Conductive deposits can cause
spark plug failure and engine misfire. Use a jewelers
file to remove deposits from the electrode gap or use
a spark plug cleaning machine to clean spark plugs.
REMOVAL
Always remove cables by grasping at the boot,
rotating the boot 1/2 turn, and pulling straight back
in a steady motion.
(1) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug.
(2) Remove the spark plug using a quality socket
with a foam insert.
(3) Inspect the spark plug condition. Refer to
Spark Plug Condition in this section.
INSTALLATION
(1) To avoid cross threading, start the spark plug
into the cylinder head by hand.
(2) Tighten spark plugs to 28 N´m (20 ft. lbs.)
torque.
(3) Install spark plug cables over spark plugs. A
click will be heard and felt when the cable properly
attaches to the spark plug.
IGNITION COILÐ2.4L
REMOVAL
REMOVAL
(1) Remove spark plug cables from coil (Fig. 7).
Always twist the coil boots to break the seal with the
coil and pull straight back on the boot.
(2) Remove ignition coil electrical connector.
(3) Remove ignition coil mounting bolts, throttle
cable bracket or clip.
(4) Remove ignition coil.
INSTALLATION
(1) Reverse the above procedure for installation.
Tighten mounting screws to 12 N´m (105 in. lbs.)
torque.
(2) Transfer ignition cables to new coil pack. The
coil pack towers and cables are numbered with cylin-
der identification.
Fig. 5 Intake Air Temperature Sensor
Fig. 6 Spark Plug Cables
8D - 18 IGNITION SYSTEMNS
DESCRIPTION AND OPERATION (Continued)
When replacing the distributor cap, transfer spark
plug wires from the original cap to the new cap one
at a time. Ensure that each wire is installed into the
tower of the new cap that corresponds to its tower
position in the original cap. Fully seat the wires into
the towers. If necessary, refer to the engine firing
order diagram.
Light scaling of the terminals can be cleaned with
a sharp knife. If the terminals are heavily scaled,
replace the distributor cap.
A cap that is greasy, dirty or has a powder-like
substance on the inside should be cleaned with asolution of warm water and a mild detergent. Scrub
the cap with a soft brush. Thoroughly rinse the cap
and dry it with a clean soft cloth.
DISTRIBUTOR ROTORÐ3.0L
Replace the rotor if it is cracked, the tip is exces-
sively burned or heavily scaled (Fig. 10).
SPECIFICATIONS
SPARK PLUG
TORQUE
DESCRIPTION......................TORQUE
Distributor Hold Down........14N´m(124 in. lbs.)
Ignition Coil Bracket..........10N´m(96in.lbs.)
Ignition Switch...............2N´m(17in.lbs.)
Spark Plugs.................28N´m(60in.lbs.)
SPARK PLUG CABLE RESISTANCEÐ3.0L
Fig. 9 Distributor Cap InspectionÐTypical
Fig. 10 Rotor InspectionÐTypical
Engine Spark Plug Gap Thread Size
3.0L RN11YC4 0.039 TO 0.044 14mm (3/4 in.) reach
CABLE Maximum
Resistance
#1 14.0K ohms
#2 10.4K ohms
#3 14.9K ohms
#4 11.5K ohms
#5 17.5K ohms
#6 10.3K ohms
Coil Lead 11.1K ohms
NSIGNITION SYSTEM 8D - 27
CLEANING AND INSPECTION (Continued)
3.3/3.8L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
FIRING ORDERÐ3.3/3.8L................. 28
REMOVAL AND INSTALLATION
CAMSHAFT POSITION SENSOR............ 31
CRANKSHAFT POSITION SENSOR.......... 30
ENGINE COOLANT TEMPERATURE SENSOR . . 32
IGNITION COIL......................... 30
KNOCK SENSORÐ3.3/3.8L................ 32
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR............................. 32SPARK PLUG CABLE SERVICEÐ3.3/3.8L
ENGINES............................ 28
SPARK PLUG SERVICEÐ3.3/3.8L ENGINES . . . 29
THROTTLE POSITION SENSOR............ 32
SPECIFICATIONS
IGNITION COIL......................... 33
SPARK PLUG CABLE RESISTANCEÐ3.3/3.8L . . 34
SPARK PLUG........................... 33
TORQUE.............................. 34
DESCRIPTION AND OPERATION
FIRING ORDERÐ3.3/3.8L
The firing order for 3.3L and 3.8L engines is 1-2-3-
4-5-6.
REMOVAL AND INSTALLATION
SPARK PLUG CABLE SERVICEÐ3.3/3.8L ENGINES
WARNING: The ignition cables should not be
removed while the engine is hot. This could cause
sever injury/burns and can cause damage to the
ignition cables.
The spark plug boot heat shield needs to be
installed correctly on the boot before being installed
on the engine (Fig. 1). If it is not installed correctly
engine misfire would occur.
Do not use pliers to pull the boot/heat shield
assembly from the spark plugs. This will damage the
shield assembly.
Spark plug boot heat shields must be replaced if
they are bent or damaged. It is extremely important
the shield is reinstalled correctly as shown. The bot-
tom of the spark plug heat shield must make contact
with the spark plug socket hex.
Firing OrderÐ3.3/3.8L
Fig. 1 Spark Plug Boot/Heat Shield Orientation
8D - 28 IGNITION SYSTEMNS
made to seal the area between the bedplate and cyl-
inder block without disturbing the bearing clearance
or alignment of these components.
GASKET DISASSEMBLY
Parts assembled with form-in-place gaskets may be
disassembled without unusual effort. In some
instances, it may be necessary to lightly tap the part
with a mallet or other suitable tool to break the seal
between the mating surfaces. A flat gasket scraper
may also be lightly tapped into the joint but care
must be taken not to damage the mating surfaces.
SURFACE PREPARATION
Scrape clean or wire brush all gasket surfaces to
remove all loose material. Inspect stamped parts to
ensure gasket rails are flat. Gasket surfaces must be
free of oil and dirt. Make sure old gasket material is
removed from blind attaching holes.
FORM-IN-PLACE GASKET APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier then using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing the material off location.
TheMopartSilicone Rubber Adhesive Sealant
gasket material or equivalent should be applied in a
continuous bead approximately 3 mm (0.120 in.) in
diameter. All mounting holes must be circled. For
corner sealing, a 3.17 or 6.35 mm (1/8 or 1/4 in.) drop
is placed in the center of the gasket contact area.
Uncured sealant may be removed with a shop towels.
Components should be torqued in place while the
sealant is still wet to the touch (within 10 minutes).
The usage of a locating dowel is recommended during
assembly to prevent smearing of material off loca-
tion.
CRANKSHAFT SPROCKET BOLT ACCESS PLUG
An Access plug is located in the right inner fender
shield. Remove the plug and insert the proper size
socket, extension and ratchet, when crankshaft rota-
tion is necessary.
ENGINE CORE PLUGS
REMOVAL
Using a blunt tool such as a drift or a screwdriver
and a hammer, strike the bottom edge of the cup
plug (Fig. 1). With the cup plug rotated, grasp firmlywith pliers or other suitable tool and remove plug
(Fig. 1).
CAUTION: Do not drive cup plug into the casting
as restricted cooling can result and cause serious
engine problems.
INSTALLATION
Thoroughly remove all rust and clean inside of cup
plug hole in cylinder block or head. Be sure to
remove old sealer. Lightly coat inside of cup plug hole
with sealer. Make certain the new plug is cleaned of
all oil or grease. Using proper drive plug, drive plug
into hole so that the sharp edge of the plug is at
least 0.5 mm (0.020 inch.) inside the lead in chamfer
(Fig. 1).
It is in not necessary to wait for curing of the seal-
ant. The cooling system can be refilled and the vehi-
cle placed in service immediately.
ENGINE PERFORMANCE
If a loss of performance is noticed, timing belt or
chain may have skipped one or two teeth. Camshaft
and crankshaft timing should be checked. Refer to
Group 9, Engine Timing belt or chain installation.
It is important that the vehicle is operating to its
optimum performance level to maintain fuel economy
and lowest vehicle emissions. If vehicle is not operat-
ing to these standards, refer to Engine Diagnosis out-
lined is this section. The following procedures can
assist in achieving the proper engine diagnosis.
(1) Test cranking amperage draw. Refer to Group
8B, Starting.
(2) Check intake manifold for vacuum leaks.
(3) Perform cylinder compression pressure test.
Refer to Engine Diagnosis, outlined in this section.
(4) Clean or replace spark plugs as necessary and
adjust gap as specified in Group 8D, Ignition System.
Tighten to specifications.
Fig. 1 Core Hole Plug Removal
9 - 2 ENGINENS
GENERAL INFORMATION (Continued)
cause of low compression unless some malfunc-
tion is present.
(11) Clean or replace spark plugs as necessary
and adjust gap as specified in Group 8, Electrical.
Tighten to specifications.
(12) Test resistance of spark plug cables. Refer to
Group 8, Electrical Ignition System Secondary Cir-
cuit Inspection.
(13) Test coil output voltage, primary and second-
ary resistance. Replace parts as necessary. Refer to
Group 8, Electrical Ignition System.
(14) Check fuel pump pressure at idle and differ-
ent RPM ranges. Refer to Group 14, Fuel System for
Specifications.
(15) The air filter elements should be replaced as
specified in Group 0, Lubrication and Maintenance,.
(16) Inspect crankcase ventilation system as out
lined in Group 0, Lubrication and Maintenance. For
emission controls see Group 25, Emission Controls
for service procedures.
(17) Inspect and adjust accessory belt drives refer-
ring to Group 7, Cooling System, Accessory Drive
Belts for proper adjustments.
(18) Road test vehicle as a final test.
CYLINDER COMBUSTION PRESSURE LEAKAGE
TEST
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Clean spark plug recesses with compressed air.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1 379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
LASH ADJUSTER (TAPPET) NOISE DIAGNOSIS
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may
cause aerated oil to enter the adjusters and cause
them to be spongy.
(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) During this time, turn engine off and let set for
a few minutes before restarting. Repeat this several
times after engine has reached normal operating
temperature.
(4) Low oil pressure.
(5) The oil restrictor pressed into the vertical oil
passage to the cylinder head is plugged with debris.
(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Faulty lash adjuster.
a. Check lash adjusters for sponginess while
installed in cylinder head. Depress part of rocker
arm over adjuster. Normal adjusters should feel very
firm. Spongy adjusters can be bottomed out easily.
b. Remove suspected lash adjusters, and disassem-
bleDo not reuse retainer caps. Do not inter-
change parts and make sure that care and
cleanliness is exercised in the handling of parts.
c. Clean out dirt and varnish with solvent.
d. Reassemble with engine oil.
e. Check for sponginess.
f. If still spongy, replace with new adjuster.
INSPECTION (ENGINE OIL LEAKS IN GENERAL)
Begin with a through visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
9 - 8 ENGINENS
DIAGNOSIS AND TESTING (Continued)
ENGINE DIAGNOSISÐPERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery. 1. Test battery. Charge or replace
as necessary.Refer to Group 8A,
Battery.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to terminals.
3. Faulty starter. Test starting system. Refer to Group
8B, Starting.
4. Moisture on ignition wires. 4. Remove moisture from wires.
5. Faulty ignition cables. 5. Replace any cracked or shorted
cables.
6. Faulty coil or control unit. 6. Test and replace as needed.
Refer to Group 8D, Ignition System
7. Incorrect spark plug gap. 7. Set gap. Refer to Group 8D,
Ignition System.
8. Contamination in fuel system. 8. Clean system and replace fuel
filter.
9. Faulty fuel pump. 9. Test fuel pump and replace as
needed. Refer to Group 14, Fuel
System.
ENGINE STALLS OR IDLES
ROUGH1. Idle speed too low. 1. Test minimum air flow. Refer to
Group 14, Fuel System.
2. Incorrect fuel mixture. 2. Refer to Group 14, Fuel System.
3. Intake manifold leakage. 3. Inspect intake manifold, manifold
gasket, and vacuum hoses. Refer to
Group 11, Exhaust System and
Intake Manifold.
4. Incorrect ignition wiring. 4. Install correct wiring.
5. Faulty coil(s) 5. Test and replace as necessary.
Refer to Group 8D, Ignition System.
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap. Refer to
Group 8D, Ignition System.
2. Contamination in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. Test and replace as necessary.
Refer to Group 14, Fuel System.
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each
cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust
system.8. Install new parts, as necessary.
9. Faulty ignition cables. 9. Replace any cracked or shorted
cables.
10. Faulty coil(s). 10. Test and replace as necessary.
Refer to Group 8D, Ignition System.
9 - 10 ENGINENS
DIAGNOSIS AND TESTING (Continued)
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE MISSES ON
ACCELERATION1. Dirty or incorrectly gapped spark
plugs.1. Clean spark plugs and set gap.
Refer to Group 8D, Ignition System.
2. Contamination in Fuel System. 2. Clean fuel system and replace
fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty coil(s). 4. Test and replace as necessary.
Refer to Group 8D, Ignition System.
ENGINE MISSES AT HIGH SPEED 1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
Refer to Group 8D, Ignition System.
2. Faulty coil(s). 2. Test and replace as necessary.
Refer to Group 8D, Ignition System.
3. Dirty fuel injector(s). Test and replace as necessary.
Refer to Group 14, Fuel System.
4. Contamination in fuel system. 4. Clean system and replace fuel
filter.
NSENGINE 9 - 11
DIAGNOSIS AND TESTING (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Misaligned or deteriorated
gaskets.1. Replace gasket(s).
2. Loose fastener, broken or porous
metal part.2. Tighten, repair or replace the
part.
3. Misaligned or deteriorated cup or
threaded plug.3. Replace as necessary.
OIL CONSUMPTION OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as
necessary. Refer to Group 25,
Emission Control Systems.
2. Worn, scuffed or broken rings. 2. Hone cyinder bores. Install new
rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check
grooves. If groove is not proper
width, replace piston.
5. Worn valve guides. 5. Ream guides and replace valves
with oversize valves and seals.
6. Valve stem seal unseated or
faulty.6. Repair or replace seal.
NSENGINE 9 - 13
DIAGNOSIS AND TESTING (Continued)