Pontiac Fiero 1988 Service Manual page 382

ENGINE ELECTRICAL 6D-1
SECTION 6D
ENGINE ELECTRICAL
CONTENTS
G e n e r a l D e s c r i p t i o n
Battery
Charging System - CS .....
Ignition System ...............
Distributor Ignition .....
Distributorless Ignition
6D-1 Cranking System 6D-2
6D
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Diagnosis 6D-3
6D-1 Battery 6D1
j Cranking System 6D2
Charging System 6D3
6D
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Ignition System 6D4
5D_1 Engine Wiring 6D5
GENERAL DESCRIPTION
The engine electrical system includes the battery,
ignition (primary and secondary), starter (and related
wiring) and the generator (and related wiring). The
accompanying diagnosis charts will aid in
trouble-shooting system faults. When a fault is traced
to a particular component, refer to that components'
section of the service manual.
BATTERY
Distributor
The High Energy Ignition (HEI) distributor with
Electronic Spark Timing (EST), used on most engines,
combines all ignition components in one unit. The
ignition coil is in the distributor cap and connects
through a resistance brush to the rotor. Another type
of HEI/EST ignition system, used on some engines,
has a separately mounted coil.
The sealed battery is standard on all cars.
The battery has three major functions in the
electrical system: First, it provides a source of energy
for cranking the engine; Second, it acts as a voltage
stabilizer for the electrical system; And third, it can, for
a limited time, provide energy when the electrical load
used exceeds the output of the generator.
CHARGING SYSTEM-CS
The CS Charging System has several sizes
available, including the CS-130 and CS-144. The
number (130 or 144) denotes the OD in mm of the
stator laminations.
CS generators use a new type regulator and a
diode trio is not used. A delta stator, rectifier bridge,
and rotor with slip rings and brushes are electrically
similar to earlier generators. A conventional pulley and
fan is used and, on the CS-130, an internal fan cools the
slip ring end frame, rectifier bridge and regulator.
IGNITION SYSTEM
Distributor Ignition
The ignition circuit consists of the battery,
distributor, ignition switch, spark plugs and primary
and secondary wiring. Refer to the Battery Section
(6D1) for battery information.
IGNITION SYSTEM
Distributorless Ignition
Distributorless ignition systems use a "waste
spark" method of spark distribution. Each cylinder is
paired with its opposing cylinder in the firing order, so
that one cylinder on compression fires simultaneously
with its opposing cylinder on exhaust. Since the
cylinder on exhaust requires very little of the available
voltage to fire its plug, most of the voltage is used to
fire the cylinder on compression. The process reverses
when the cylinders reverse roles. There are two coils
for a 4-cylinder engine (Direct Ignition System - DIS)
and three coils for a 6-cylinder engine (C
3
I).
Ignition Timing
Timing specifications for each engine are listed in
Section 6E. When using a timing light, connect an
adapter between the No. 1 spark plug and the No. 1
spark plug wire, or use an inductive type
Secondary Wiring
The spark plug wiring used with ignition systems
is a carbon impregnated cord conductor, encased in an
8MM (5/16") diameter silicone rubber jacket. The