GMC 1976 ZEO 6083 Maintenance Manual page 425

FD.E CENTER ELECTRODE
CENTER ELECTRODE
SQUARE AFTER CLEANING
ROUNDED AFTER AND BEFORE SETTING
NORMAL USE
SPARK PLUG GAP
A-1877
Figure 45-Spark Plug Electrodes
to the center terminal of the ignition coil . Low ten-
sion wires are the small wires connected to the pri-
mary terminals on the coil, and to the primary
terminal at the distributor.
High tension wires have a built-in resistance of
approximately 4,000 ohms per foot except coil wire
which is 8,000 ohms per foot.
At regular intervals wires should be inspected for
ENGINE ELECTRICAL
6Y- 45
damage. If insulation is cracked or swollen, wires
should be replaced.
IGNITION SWITCH
The electrical switching portion of the assembly
is separate from the key and lock cylinder . However,
both are synchronized and work in conjunction with
each other through the action of the actuator rod
assembly . For a complete explanation of the key and
lock cylinder, and the actuator rod assembly, refer to
the Steering section of this manual.
The ignition switch is key operated through the
actuator rod assembly to close the ignition primary
circuit and to energize the starting motor solenoid
for cranking . The ignition switch has five positions :
OFF, LOCK, ACCESSORY, RUN and START.
OFF is the center position of the key-lock cylinder,
and lock is the next position to the left . ACCES-
SORY is located one more detent to the left of
LOCK . Turning the key to the right of the OFF
position until spring pressure is felt will put the igni-
tion in the RUN position, and when turned fully to
the right against spring pressure, the switch will be
in the START position .
In the RUN position, the ignition primary circuit
is activated through a resistance wire. The ignition
resistor wire is used in the ignition running circuit to
reduce the voltage to the ignition coil . The resistor
wire is bypassed when the engine is being started.
The purpose of this is to compensate for the drop in
voltage which occurs as the result of the heavy drain
on the battery during starting, and to provide a hot-
ter spark for starting .
BREAKER POINT IGNITION SYSTEM
SPECIFICATIONS
DISTRIBUTOR
Make .... . ... . . ... . . ... . . ... . .... . ... . . . .. . . . . .. .... . . .. . . . .. . . .. . . .. . . ... . . .. . . . .. . . .... .... . . . .. . . .... . ... . . . .. . . ... . .. Delco-Remy
Model No. . .. . . .... . ... . . ... . . ... . . ... . .... . ... . . .. . . . ... . ... . .. . . ... . . .. . . . ... . .... . . .. . . . ... . .... . . .. . . . ... . .... .... . . .. . .1112172
Rotation (Viewed at Rotor) . . . .. . . .... .... . . .. . . . .. . . .. . . .. . . ... . . .. . . . .. . . .... . ... . . . .. . . .... . ... . . . .. Counterclockwise
Point Opening (In.) . . ... . .... . ... . . .. . . . ... . .... . ... . . ... . ... . ... . .. .. . ... . . .. . . . ... . .... . . .. . . . .... .... . . .. . . . ... . .... . ... . .... ... .016
Cam Angle (Degrees) . . .... . ... . . .. . . . ... . .... . ... . . ... . ... . ... . .... . ... . . .. . . . ... . .... . . .. . . . ... . .... . ... . . . .. . . .... . ... . .... .... . 30
Centrifugal Advance
Start Distributor (Degrees) . . . .. . . ... . . ... . .... .... . ... . .... .... . ... . . ... . . .... . . .. . . . .. . . .... . ... . . ... . . ... . . ... . .... .... . 0-2
R.P.M. ... . ... . . ... . . ... . .... . ... . . . .. . . ... . . ... . .... .... . ... . .... . ... . ... . . . .. . . .... . ... . . ... . . ... . . ... . .... . . .. . . . ... . .... ... 575
Intermediate Distributor (Degrees) .. . . .... .... . ... . .... .... . ... . . ... . . ... . . ... . . ... . . ... . . ... . .... . ... . . . ... . ... 3.5-5 .5
R.P.M. ... .... . . .. . . . ... . .... . ... . . . .. . . ... . . ... . .... .... . ... . ... . .... . ... . . ... . . ... . . ... . . ... . . ... . . ... . . ... . . .. . . . ... . ... . . 1000
Maximum Advance Degrees ... . . ... . . ... . .... .... . ... . .... .... . ... . . ... . . ... . . ... . . ... . . ... . . ... . .... . ... . . . ... . ... . ... . . 7-9
R .P.M. .. . .... . ... . . . .. . . ... . . ... . .... . ... . . . .. . . ... . ... . . .. . . ... . ... . . ... . .... . ... . . . ... . .... . . .. . . . ... . .... . ... . . ... . . .. . . . 1700
Firing Order. . ... . . .... .... . ... . . . ... . .... . ... . . ... . . ... . . ... . .. . . ... . ... . . ... . .... . ... . . .... . .... . ... . . . .. . . .... . ... . 1-8-4-3-6-5-7-2
(*) Set with Vacuum in Retard Position .