Pontiac tempest 1968 Service Manual page 368

E N G I N E E L E C T R I C A L
6E-19
IGNITION TIMING
Correct timing marks are on the front engine
covers and harmonic balancer (Figs. 6E-29, 6E-30).
Due to vacuum advance at idle, it Is imperative
to disconnect distributor vacuum advance line before
setting ignition timing.
F i g . 6 E - 2 9 Timing Marks on 6 Cylinder Engine
Fig. 6E-30 Timing Marks on V - 8 Engine
At time spark is adjusted, the general appearance
of breaker points should be observed. If smudge line
appears on point support and breaker plate just be­
neath points, burned points (from oil or crankcase
vapor between points) are very probable. Points
which have gone several thousand miles will have a
rough surface, but this does not mean points are
worn out. The roughness between points matches so
that a - large contact area is maintained and points
will continue to provide satisfactory service. If dirt
or scale is present, points should be cleaned with a
few strokes of a clean, fine-cut, contact file. Do not
attempt to remove all roughness or dress point sur­
faces down smooth. Never use emery cloth or sand­
paper to clean points. If points are burned or badly
pitted, ~ they should be replaced and cause of this
condition found and corrected. If this is not done
new points will also burn and pit in a short time.
Adjust ignition timing as follows:
1. Adjust breaker point gap.
2. Connect power timing light.
3. Loosen distributor clamp screw and rotate
distributor until power timing light shows that the
proper mark on the cover lines up with the mark
on the harmonic balancer. Tighten distributor clamp
screw. The timing specifications for various engines
are listed below:
6-cyl. 4-bbl. 5°BTDC
6-cyl. 1-bbl. 0°TDC
V-8 (All) 9°BTDC
IGNITION AND STARTING SWITCH
The ignition and starting switch is key-operated to
close the ignition primary circuit and to energize the
starting motor solenoid for cranking.
The ignition switch used on Pontiac and Tempest
has four positions, O F F when the key is straight up
and down, ACCESSORY when pushed in and turned to
the left, ON when turned to the right until spring
pressure is felt, and START when turned fully to the
right against spring pressure.
With the switch in either ACCESSORY or ON posi­
tions the following electrical circuits are activated:
stop lights, air conditioning, directional signals,
parking brake warning light, radio, back-up lights,
heater and defroster, and electric windshield wiper.
In the ON position the ignition primary circuit is
activated through the resistance.
There are eight terminals on the back of switch
(Figs. 6E-31-32). The terminal marked BAT is con­
nected to the battery and supplies power to the
switch. The accessory terminal supplies power to
the accessories when the switch is in ACC or run­
ning positions. The SOL terminal supplies power to
the solenoid to activate the starter in start position.
The terminal marked GRD completes the test c i r ­
cuit for the temperature HOT indicator bulb when the
switch is turned to start position.