Pontiac tempest 1968 Service Manual page 365

6E-16
1968 P O N T I A C SERVICE MANUAL
NOTE: Providing dwell meter is accurate and is
used correctly, points can be set very accurately.
Several design features such as use of upper shaft
bushing as a bearing for breaker plate and con­
struction of advance mechanism have made this
possible.
Alternate Method
Turn adjusting screw (clockwise) until engine be­
gins to misfire. Then turn screw one-half turn in
opposite direction (counterclockwise). This will give
proper dwell angle.
point alignment of service contact set have been pre-
adjusted at factory. Only point opening requires
adjusting after replacement.
Replace contact set as follows:
1. Remove two attaching screws which hold base
of contact set assembly in place.
2. Remove condenser lead and primary lead from
nylon insulated connection (Fig. 6E-25) in contact
set,
REMOVE
1. Disconnect distributor-to-coil primary wire.
2. Remove distributor cap.
3. Crank engine so rotor is in position to fire No.
1 cylinder and timing mark on harmonic balancer is
indexed with the proper mark on the timing chain
cover, Fig„ 6E-27 and 6E-30.
4. Remove vacuum lines from distributor.
5. Remove distributor clamping screw and hold-
down clamp.
6. Remove distributor and distributor to block
gasket. It will be noted that rotor will rotate as
distributor is pulled out of block. Note relationship
of rotor and distributor housing after removal, so
that rotor can be set in same position when distribu­
tor is being installed.
NOTE: Always set distributor in upright position
so oil from distributor shaft will not run out onto
breaker plate and points.
INSPECT
With distributor removed from vehicle it is ad­
visable to place distributor in a distributor testing
machine or synchroscope. When mounting distributor
in tester, first secure gear in drive mechanism, then
push distributor housing down toward gear to take up
end play between gear and housing, and finally secure
housing in tester. Test distributor for variation of
spark, correct centrifugal and vacuum advance, and
condition of contacts. This test will give valuable in­
formation on distributor condition and indicate parts
replacement which may be necessary.
REPLACE CONTACT SET
The contact point set is replaced as one complete
assembly. The breaker lever spring tension and
CONDENSER
LEAD CLIP
LEAD ,
GROUND LEAD
F i g . 6 E - 2 5 Arrangement of Leads
3. Replacement is reverse of removal.
CAUTION: Make sure condenser lead and pri­
mary lead are located as in Fig. 6E-25. Leads
must be properly located to eliminate interference
between leads and cap, weight base or breaker
plate.
4. Apply trace of petrolatum to breaker cam.
DISASSEMBLE DISTRIBUTOR
1. Remove r o t o r by removing two attaching
screws, lockwashers, and flatwashers (Fig. 6E-26).
NOTE: It will be observed that rotor is doweled
to weight base so that it can be installed in only
one position.
2. Remove both weight springs and both advance
weights.
3. Remove retaining pin from gear by driving it
out of gear with a drift and hammer.