Spark Plugs; Ignition Coils - Chrysler 1998 Viper RT/10 Owner's Manual

8D - 2 IGNITION SYSTEM
SR
DESCRIPTION AND OPERATION ( C o n t i n u e d !
through the Automatic Shutdown (ASD) Relay. The
P C M also controls the ground circuit for the ignition
coils. B y switching the ground p a t h for the coil on
and off, the P C M adjusts ignition t i m i n g to meet
changing engine operating conditions.
D u r i n g the crank-start period the P C M advances
ignition t i m i n g a set amount. D u r i n g engine opera-
tion the following inputs determine the amount of
spark advance provided by the P C M .
• I n t a k e air temperature
• Coolant temperature
© Engine R P M
® Available manifold vacuum
• Throttle position sensor
The P C M also regulates the fuel injection system.
Refer to the Fuel Injection sections of Group 14.
Fig. 1 Powertrain Control Module
SPARK PLUGS
The Viper 8.0L V-10 engine uses resistor spark
plugs. They have resistance values of 6,000 to 20,000
ohms w h e n checked w i t h at least a 1000 volt tester.
Remove the spark plugs and examine t h e m for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged i n the order
i n w h i c h they were removed from the engine. A n iso-
lated p l u g displaying an abnormal condition indicates
t h a t a problem exists i n the corresponding cylinder.
Replace spark plugs at the intervals recommended i n
Group O .
Spark plugs t h a t have l o w mileage may be cleaned
and reused i f not otherwise defective. Refer to the
Spark Plug Condition section of this group. After
cleaning, file the center electrode flat w i t h a small
flat file or jewelers file. Adjust the gap between the
electrodes (Fig. 2) to the dimensions specified i n the
chart at the end of this section.
T A P E R
G A U G E
803f5851
Fig. 2 Setting Spark Plug Electrode Gap—Typical
Always t i g h t e n spark plugs to the specified torque.
Over t i g h t e n i n g can cause distortion resulting i n a
change i n the spark plug gap. Tighten spark plugs to
28 N - m (20 ft. lbs.) torque.
S P A H PLUG CA1LES
Spark Plug cables are sometimes referred to as
secondary ignition wires. The wires transfer electri-
cal current from the electronic ignition coils to the
individual spark plug at each cylinder. The nonmetal-
lic spark p l u g ' cables have b u i l t i n resistance. The
cables provide suppression of radio frequency emis-
sions from the ignition system.
Check the spark p l u g cable connections for good
contact at the coil and spark plugs.' Terminals should
be fully seated over the coil or spark plug. The nip-
ples and spark plug covers should be i n good condi-
tion. Nipples should fit t i g h t l y on the coil and spark
plug covers should fit t i g h t around spark plug insu-
lators. Loose cable connections permit corrosion t h a t
increases resistance.
IGNITION COILS
W A R N I N G : T H E E L E C T R O N I C I G N I T I O N S Y S T E M
G E N E R A T E S A P P R O X I M A T E L Y 40,000 V O L T S . P E R -
S O N A L I N J U R Y C O U L D R E S U L T F R O M C O N T A C T
W I T H T H I S S Y S T E M .
The electronic ignition system uses two epoxy filled
coil packs mounted on a bracket at the rear of the
engine (Fig. 3) and (Fig. 4 ) . The coil pack on the left
side, contains three separate coils and fires cylinders