Ignition System - Breaker Point; Distributor Identification Number - Ford VSG-411 Service Manual

2-01
Ignition System
2-01
PART
2 Ignition System -
Breaker Point
COMPONENT INDEX
Page
COMPONENT INDEX Page
IDENTIFICATION ...................... 2-01
REMOVAL AND INSTALLATION (Cont' d.)
DESCRIPTION
.........................
2-01
Spark Plugs ........................ 2-06
DIAGNOSIS AND TESTING
..............
2-02
Distributor
......................... 2-06
Spark Intensity Tests ..................
2-02
Vacuum Diaphragm
.................. 2-07
Ignition System Tests
................. 2-02
CLEANING AND INSPECTION ........... 2-07
Distributor Tests - On Engine
.......... 2-03
Spark Plugs ........................
2-07
ADJUSTMENTS
.......................
2-04
Distributor
......................... 2-07
REMOVAL AND INSTALLATION
..........
2-05
Distributor Cap and Rotor .............. 2-07
Breaker Points and/or Condenser
........
2-05
Ignition Wires .......................
2-07
Spark Plug Wire
..................... 2-06
Ignition Coil ........................
2-07
IDENTIFICATION
The distributor identification number is stamped on the distrib-
utor housing. The basic part number for distributors is 12 100. To
procure replacement parts, it is necessary to know the part number
prefix and suffix (Figure 1).
Always refer to the Parts Catalog for parts usage and inter-
changeability before replacing a distributor or a component part
for a distributor.
PART NUMBER
PREFIX
PART NUMBER SUFFIX
FIG. 1 Distributor identification
DESCRIPTION
The distributor is located on the right side of the engine. It is
equipped with a vacuum and a centrifugal advance unit to control
ignition timing. The vacuum advance governs the ignition timing
(spark advance) during low engine speeds, or low engine load-
ings. The centrifugal advance, in combination with the vacuum
advance, controls the ignition timing at higher engine speeds or
heavy engine loadings to provide the correct ignition timing for
maximum engine performance.
The diaphragm is connected to the movable breaker plate by a
link. An increase in vacuum will move the diaphragm against the
advance diaphragm spring tension, causing the movable breaker
plate to pivot opposite the distributor rotation. Thus, ignition
timing is advanced, and this is calculated to occur during normal
road-load operation, but not during deceleration or idle.
The ignition system consists of a primary (low voltage) and a
secondary (high voltage) circuit (Figure 2).
The primary circuit consists of the:
1. Battery
2. Ignition switch
3. Primary circuit resistor
4. Primary windings of the ignition coil
5. Breaker points
6. Condenser
The secondary circuit consists of the:
1. Secondary windings of the ignition coil
2. Distributor rotor
3. Distributor cap
4. High tension (spark plug) wires
5. Spark plugs
FIG. 2 Ignition System Circuit
A - Battery
B - ignition Switch (Off Position)
The ignition system is of the ballast resistor type and uses a
seven volt coil. Under normal operating conditions the 12 volt
feed to the coil is reduced by a ballast resistor wire to seven volts
(Figure 3).
During starting, however, the ballast resistor wire is by-passed
allowing full available battery voltage to be fed to the coil. This
ensures that during cold starting, when the starter motor current
draw would be high, sufficient voltage is still available at the coil
to produce a powerful spark (Figure 4).