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9-8
GROUP 9-
IGNITION SYSTEM
If
the distributor is in the engine
place the rubbing block on the peak
of the cam by proceeding as follows:
Disconnect the brown wire and the
red and blue wire from the starter re-
lay and, with the ignition switch off,
crank the engine by using an auxiliary
starter switch between the S and bat-
tery terminals of the starter relay.
Insert the correct blade of a clean
feeler gauge between the breaker
points (Fig. 11 )
.
Apply a light film of distributor
cam lubricant (MIC66-A) to the
Feeler Gouge
FIG. 11
-Adjusting New
Breaker Point Gap
cam when new points are installed.
Do not use engine oil to lubricate
the distributor cam.
Set the ignition timing.
If
a scope or a dwell meter is used
to
.
adjust new points, be sure the
points are in proper alignment. Also,
set the contact dwell to the low set-
ting. New points must be set to the
low dwell as the rubbing block will
wear down slightly while seating to
the
cam.
To check and adjust the breaker
points with a scope, refer to Ignition
System Tests.
To check and adjust the breaker
points with a dwell meter, refer to
Distributor Tests.
BREAKER POINT SPRING
TENSION ADJUSTMENT
AUTO LITE
BREAKER POINT SPRING
TENSION ADJUSTMENT
Correct breaker point spring ten-
sion is essential to proper engine op-
eration and normal breaker point
life.
If
the spring tension is too great,
rapid wear of the breaker arm rub-
bing block will result, causing the
breaker point gap to close up and re-
tard the spark timing.
If
the spring
tension is too
weak,
the breaker arm
will flutter at high engine rpm result-
ing in an engine miss.
To check the spring tension on
either the pivot-type or the pivotless
breaker points, place the hooked end
of the spring tension gauge over the
movable breaker point. Pull the gauge
at a right angle (90°) to the movable
arm until the breaker points just start
to open (Fig. 12 ) .
If
the tension is
not within specifications, adjust the
spring tension on the pivot-type
points or replace the breaker point
assembly on the pivotless points.
ng
Breaker Point Spring
Tension
To adjust the spring tension (Fig.
13)
1.
Disconnect the primary or dis-
tributor lead wire and the condenser
lead.
2.
Loosen the nut holding the
spring in position. Move the spring
toward the breaker ann pivot to de-
crease tension and in the opposite di-
rection to increase tension.
3. Tighten the lock
nut,
and then
check spring tension. Repeat the ad-
justment until the specified spring
tension is
obtained.
4. Install the primary or
distri~
butor lead wire and the condenser
lead.
IGNITION TIMING
TIMING MARK LOCATIONS
There are two methods of showing
the timing position. Both methods
use the cranksl.taft damper and a tim-
ing pointer.
One method uses degree marks on
the crankshaft pulley (Fig.
14)
.
These
degree marks range from 0° or top
dead center (TDC) to some value
before top dead center
(BTDC).
When checking the timing, the cor-
MORE TENSION
TENSION SPRING
LESS TENSION
FIG. 13
-Adjusting
Breaker Point Spring
Tension
rect degree mark should be in line
with the timing pointer when the
timing light flashes
.
The other method uses degree
marks on the timing pointer
(Fig.
15). These also range from
0°
or top
dead center (TDC) to some value be-
fore top dead
center (BTDC).
When
checking the
timing,
the correct de-
gree mark should be in line with the
timing mark on the crankshaft pulley
when the timing light flashes
.
ADJUSTMENT
To check and adjust the timing
with a power timing light, proceed
as follows:
12019-A
FIG. 14
-Typical
V-8
Engine Timing Marks
1.
Remove the plug wire from the
number 1 spark
plug.
2.
Install the spark plug adaptor
on the spark plug.
3. Connect the plug wire to the
spark plug adaptor.
4. Clamp the timing light spark
plug lead to the spark plug adaptor.
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