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IGNITION SYSTEMS
8D - 3
W i t h t h e engine n o t r u n n i n g , connect one end o f a
test probe t o a good g r o u n d . S t a r t the engine and r u n
t h e other e n d o f t h e test probe along t h e entire
l e n g t h of a l l spark p l u g cables. I f cables are cracked
or punctured, there w i l l be a noticeable spark j u m p
f r o m t h e damaged area t o t h e test probe. T h e cable
r u n n i n g f r o m t h e coil t o t h e distributor cap can be
checked i n t h e same manner. Cracked, damaged or
f a u l t y cables should be replaced w i t h resistance type
cable w h i c h can be i d e n t i f i e d b y the words "Electron-
ic Suppression" p r i n t e d o n the cable jacket.
Use a n Ohmmeter (tool C-4845 or an equivalent) to
test for open circuits, excessive resistance or loose
t e r m i n a l s . Remove t h e d i s t r i b u t o r cap from t h e dis-
t r i b u t o r — D o not remove cables f r o m cap. Remove ca-
ble from spark p l u g . Connect ohmmeter to spark
p l u g t e r m i n a l o f cable a n d to corresponding electrode
i n d i s t r i b u t o r cap. Resistance should be w i t h i n spec-
ifications shown i n t h e resistance chart. I f not, re-
move cable f r o m d i s t r i b u t o r cap tower a n d connect
ohmmeter t o the t e r m i n a l ends of cable. I f resistance
is s t i l l n o t w i t h i n specifications, replace t h e cable.
Test a l l spark p l u g cables i n t h i s manner.
SPARK PLUG CABLE
RESISTANCE
MINIMUM
MAXIMUM
250 Ohms Per Inch
1000 Ohms Per Inch
3000 Ohms Per Foot
12,000 Ohms Per Foot
J908D-43
To test coil t o d i s t r i b u t o r cap cable, do not remove
t h e cable f r o m the cap. Connect t h e ohmmeter to t h e
rotor b u t t o n (center contact) and the t e r m i n a l a t t h e
coil end o f t h e cable. I f resistance is not w i t h i n spec-
ifications i n t h e resistance chart, remove t h e cable
f r o m t h e d i s t r i b u t o r cap a n d connect the ohmmeter
to the t e r m i n a l ends o f t h e cable. I f resistance is s t i l l
not w i t h i n specifications, replace t h e cable. Inspect
t h e coil tower for cracks, corrosion or o i l leaks.
Replace cables one a t a t i m e to ensure t h a t the cor-
rect f i r i n g order is m a i n t a i n e d . Route the new cables
i n t h e same manner as t h e o r i g i n a l cables keeping
t h e m away f r o m accessory drive pulleys and exhaust
manifolds securing t h e m i n the proper retainers.
To remove cables f r o m spark plugs, t w i s t t h e r u b -
ber protector boot approximately 1/2-turn to break
t h e seal. Grasp t h e boot a n d p u l l i t from t h e p l u g
w i t h a s t r a i g h t and steady p u l l . Do not p u l l on t h e
w i r e i t s e l f because t h i s w i l l damage t h e conductor
and t e r m i n a l connection. Do not use pliers to remove
t h e cable.
To remove cables f r o m t h e d i s t r i b u t o r cap or i g n i -
t i o n coil tower, loosen t h e boot first, t h e n grasp t h e
upper p a r t of the boot and the cable and g e n t l y p u l l
s t r a i g h t up.
W h e n i n s t a l l i n g new cables, p i n c h t h e protective
nipple to release a n y a i r trapped between t h e tower
and the nipple (Fig. 5 and 6).
Fig. 6 Coil Cable to Coil Installation
SPARK PLUGS
Remove t h e spark plugs a n d examine t h e m for
b u r n e d electrodes and fouled, cracked or b r o k e n por-
celain insulators. Keep plugs arranged i n t h e order
i n w h i c h they were removed from the engine. A n iso-
lated p l u g displaying a n abnormal condition i n d i -
cates t h a t a problem exists i n t h e corresponding
cylinder. Replace spark plugs a t the i n t e r v a l s recom-
mended i n t h e maintenance chart i n Group 0.
Spark plugs t h a t have low milage m a y be cleaned
and reused i f not otherwise defective. Refer to t h e
Spark P l u g Condition section of t h i s group. A f t e r
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