Ford Thunderbird 1958 User Manual

1-44
GROUP
1-POWER PLANT
PART
2
IGNITION
SYSTEM
Section
Page
1
Trouble
Shooting
1-44
2
Ignition
System
Testing
1-45
3
Distributor
Tests,
Adjustments,
and
Minor
Repairs 1-49
4
Distributor
Overhaul
1-52
The
purpose
of
the
ignition
system is
to
transform low
voltage
electricity
from the
electrical
supply
system to surges
of
high
voltage
electricity
and
to
distribute
this high
voltage
to
the proper
spark
plug
at
the
right
time.
The
ignition
system
consists of a
primary
(low
voltage)
and
a second
ary
(high
voltage)
circuit
(Fig.
1).
The
battery,
ignition
switch,
primary
cir
cuit
resistor,
primary
windings of
the
ignition
coil,
breaker
points,
and the
condenser
are in the
primary
circuit.
The
secondary
circuit is
composed of
the
secondary
windings of the igni
tion
coil,
distributor
rotor,
distribu
tor
cap,
high
tension
wires,
and
the
spark
plugs.
When
the breaker points
are
closed,
the
primary
or
low
voltage
current
flows from
the
battery
through the
ignition switch
to the
primary
wind
ings
in the
coil,
then to ground
through
the closed breaker
points.
When the breaker points
open,
the
magnetic field built
up
in the
primary
windings
of the
coil moves through
the
secondary
windings of the coil
producing
high
voltage
current.
High
voltage
current is
produced
each time
the
breaker points open.
The
high
voltage flows through the
coil high
tension lead to the distributor
cap
where
the
rotor distributes it to one
of
the
spark
plug
terminals in
the
distributor
cap. This process is re
peated
for
every
power stroke of the
engine.
IGNITION
/l^.
SWITCH
acc^JTXam
I
r
S*-**K*
DISTRIBUTOR
%&>L
SPARK
PLUG
PRIMARY
CIRCUIT
SECONDARY
CIRCUIT
FIG.
1
Ignition
Circuit
1182-C
TROUBLE
SHOOTING
Ignition system
troubles are caused
by
a failure in the
primary
and/
or
the
secondary
circuit,
or
incorrect igni
tion timing.
PRIMARY
CIRCUIT
A break down or
energy
loss in the
primary
circuit can be caused
by:
1.
Defective
primary
wiring.
2.
Burned
breaker points or
im
properly
adjusted
breaker points.
3.
A defective
coil,
resistor,
or
con
denser.
SECONDARY
CIRCUIT
A break
down
or
energy
loss in the
secondary
circuit can
be caused by:
1. Fouled or broken spark
plugs,
or plugs
incorrectly
adjusted.
2. Defective high
tension wiring.
3.
High-tension leakage
across the
coil,
distributor
cap,
or rotor.
IGNITION
TIMING
Incorrect
ignition
timing
can
be
caused by:
1.
Timing incorrectly
adjusted.
2.
Distributor
bushing
and/or
shaft
worn,
or a bent
distributor shaft.
3.
Defective vacuum
advance sys
tem.
4.
Defective centrifugal advance.
5.
Preignition
(caused
by
spark
plugs
of
the
wrong
heat
range),
im
properly
adjusted
plugs,
etc.
If
the
cause of
engine trouble has
been
traced to
the
ignition system
(page
1-7),
refer to
the
trouble in
Table 1
and check
the items
listed
under
the trouble.
The causes
of
the
troubles
are listed in
the order
of
their
probable
occurrence;
therefore,
the
items
should
be
checked
in
the
order
listed.
TABLE
1
Ignition System
Trouble
Shooting
ENGINE
CRANKS
NORMALLY,
BUT
WILL
NOT
START
To determine if
the cause of the
trouble is in
the
primary
or
the
sec
ondary
circuit,
pull
the coil
wire
from the
top
of the
distributor and
hold
it
approximately
Ve
inch from
the cylinder
head,
then with
the
igni
tion
on
and
the
engine
turning
over,
check for a spark.
If the spark is
good,
check the ignition timing.
If
the
spark is good and
the
igni
tion
timing
is
not
at
fault,
the cause
of the
trouble
is
probably
in
the:
Distributor cap.
Rotor.
Spark
plug
wires.
If
there
is
no
spark or a
weak
spark,
the cause
of the
trouble
is
probably
in the:
Primary
circuit.
Coil
to distributor high
tension
lead.
Coil.

Ford Thunderbird 1958 Specifications

General

Brand	Ford
Model	Thunderbird 1958
Category	Automobile
Language	English