Buick LeSabre 1965 Service Manual page 610

1 0 - 4 0 SPARK PLUGS AND WIRES
ELECTRICAL SYSTEMS
Figure 10-46—Installing Spark Plug
Wires in Cap-300 Engine
housing while cranking engine
with starter. After distributor
tang snaps into slot in oil pump
shaft, start timing again from
Step 1, l e a v i n g distributor
installed.
3. Connect primary wire to coil.
4. Rotate distributor counter-
clockwise slightly until contact
points just start to open.
CAUTION: This must be done
very carefully or engine will not
start.
5. Install distributor cap. Make
sure that spark plug wires are
correctly installed in distributor
cap, through clips on rocker arm
covers, and on spark plugs. See
Figure 10-46 or 10-47.
b. Finish Timing
(Engine Running)
Contact point dwell angle should
always be checked before adjust-
ing ignition timing.
1. Connect a 12-volt power timing
light to No. 1 spark plug, using a
suitable adapter and following the
instructions of the instrument
manufacturer. CAUTION: Be
careful not to puncture wire or
boot as this would start a high
voltage leak.
2. Connect a tachometer from
distributor terminal of coil to
ground.
3. Start engine and adjust contact
point dwell angle to 30 degrees.
While engine is warming up, make
certain that spark plug wires are
pushed all the way down into the
distributor cap terminals and onto
the spark plugs. Nipples must be
pushed firmly over the terminals
and boots over the spark plugs.
4. When engine temperature is
normal, adjust engine idle speed
and mixture. See paragraph 3-8.
5. Check i d l e stator s w i t c h
setting and adjust if necessary.
See paragraph 3-9.
6. Disconnect vacuum hose.
7. Direct beam of timing light on
the timing indicator and edge of
harmonic balancer. Turn distrib-
utor slowly until yellow mark on
balancer is halfway between the
"0" and "5" degree marks on
timing indicator. (Dual 4-barrel
cars with automatic transmission
are timed at 12 degrees.) Tighten
clamp bolt securely. See Figure
10-
8. Recheck timing mark.
9. Reconnect vacuum hose and
recheck idle.
1 0 - 3 6 SPARK PLUG AND
WIRE SERVICE
a. Rempve and Inspect
Spark Plugs and Wires
1. To disconnect wires, pull only
on boot because pulling on wire
might cause separation of the
core of the wire. Remove spark
plugs and gaskets using a 13/16"
deep socket wrench. Use care in
this operation to avoid cracking
spark plug insulators.
2. Carefully inspect the insula-
tors and electrodes of all spark
plugs. Replace any spark plug
which has a cracked or broken
insulator, or which has loose
electrodes. If the insulator is
worn away around the center
electrode, or the electrodes are
burned or worn, the spark plug
is worn out and should be dis-
carded. Spark plugs which are in
good condition except for carbon
or oxide deposits should be thor-
oughly cleaned and adjusted.
3. The spark plug wires are of a
special resistance type. The core
is carbon-impregnated linen. This
wire is designed to eliminate
radio and television interference
radiation, but is also superior in
resistance to cross-fire. The re-
sistance type wire, however, is
more easily damaged than copper
core wire. For this reason care
must be taken that the spark plug
wires are removed by pulling on
the spark plug boots rather than
on the wire insulation. Also, when
it is necessary to replace a spark
plug boot, the old boot should be
carefully cut from the wire and a
small amount of silicone lubri-
cant used to aid in installing the
new boot. If the wire is stretched,
the core may be broken with no
evidence of damage on the outer
insulation. The terminal may also
pull off the wire. If the core is
broken, it will cause missing. In
the case of wire damage, it is
necessary to replace the com-
plete wire assembly as a satis-
factory repair cannot be made.
4. Wipe ignition wires with cloth
moistened with kerosene, and wipe
dry. Bend wires to check for
brittle, cracked, or loose insula-
tion. Defective insulation w i l l
permit missing or cross-firing
of engine, therefore defective
wires should be replaced.
Figure 10-47—Installing Spark Plug
Wires in Cap-401 and 425 Engines