Page 211
311-2
Battery
The battery is in satisfactory condition if the open-circuit
voltage is at least 12.4 volts. If the open-circuit voltage is at
this level or above, but the battery still lacks power for starting,
make a load voltage test to determine the battery's service
condition. If the open-circuit voltage is below 12.4 volts, recharge the battery. If the battery cannot be recharged to at
least 75%, it should be replaced.
Load Voltage Testing
A load voltage battery test is made by connecting a specific
resistive load to the battery terminals and then measuring
voltage. The test requires a special tester and can generally
be performed quickly and inexpensively by an authorized
Saab dealer or qualified repair facility. The battery should be
fully charged for the most accurate results. If the equipment is
available, disconnect the negative (-) battery cable. Then apply a 200 Amp load for 15 seconds and measure the battery's
voltage. If the voltage is below that listed, the battery should
be replaced.
WARNING
Always wear protective goggles and clothing when perfonning
a load test.
BATTERY CHARGING
Discharged batteries can be recharged using a battery
charger, but a battery can never be charged to a voltage in excess of that which it is capable of producing electro-chemically. Prolonged charging causes gassing that will evaporate the
electrolyte to a level that can damage the battery.
Always read and follow the instructions provided by the battery charger's manufacturer. Do not use a charger if the instructions are not available. Table b lists charging rates and
times that should be followed when charging batteries.
WARNING
The gasses given off by the battery during charging are explosive. Do not smoke. Keep open flames away from the top of
the battery, and prevent electrical sparks by turning off the battery charger before connecting or disconnecting it.
CAUTION
Always disconnect a battery cable when using a battery
charger. This will prevent damage to solid-state components.
Table b. Battery Charging Specifications
Battery load test minimum voltage
• (200 amp load for 15 seconds)
9.6 Vat 80°F (2?OC)
9.5 Vat 60°F (16°C)
9.3 Vat 40°F (4°C)
8.9 Vat 20°F (-JOC)
8.5 Vat O°F (-18°C)
If the battery quickly becomes discharged, there may be a
fault in the charging system or in the electrical system. See
321 Alternator and Charging System for charging system
tests. On all models, be certain that the appropriate heat
shields are securely attached to the battery.
NOTE
If the key is left in the ignition switch, a battery draw of about
40 milliamps will discharge the battery over a period of time.
BA TTERY CHARGING
Charging rate (Iowmaintenance batteries)
Specific
gravity
Approximate
charging time
Fast charge
(at 80% to 90% of battery's
capacity, example: 44 to 50
amperes for a 55-ampere
hour battery)
1.150 or less
1 hour
1.150 to 1.175
3/4 hour
1.1 75 to 1.200
1/2 hour
1.200 to 1.225
1/4 hour
Above 1.225
Slow charge
only, to a
specific gravity
of 1.250 to
1.265
Slow charge
(at 10% of battery's
capacity, example: 5.5
amperes for a 55-ampere
hour battery)
Page 212
Alternator and Charging System
321-1
321 Alternator and Charging System
General
321-1
Charging System Troubleshooting
321-1
321-1
Charging System Quick-check
GENERAL
The charging system consists of a belt-driven 14-volt alternator and a voltage regulator. The voltage regulator, which is
mounted on the alternator, also serves as the alternator brush
holder. The charging system provides the current necessary
to keep the battery charged and to operate the car electrical
accessories.
To prevent damage to the alternator or regulator when making tests or repairs, make all connections with negative H to
negative, and positive (+) to positive. Even momentary contact with a conductor of the wrong polarity can damage the alternator's diodes.
Please read the following cautions before doing any work
on the charging system or alternator.
CAUTION
• Never operate the engine with the battery disconnected.
Never operate the alternator with its output terminal (8+ or 30)
disconnected and the other terminals connected. Never short,
bridge, or ground any terminals of the charging system.
• Always disconnect the negative (-) battery cable before removing the alternator. This will prevent an accidental short
from one of the alternator terminals.
• Do not reverse the polarity of the battery. Damage to the alternator will result.
• Always disconnect both battery cables before doing any
electric (arc) welding to the car.
CHARGING SYSTEM
TROU BLESHOOTING
Charging system trouble is indicated by an illuminated alternator warning light on the instrument panel, or by an underor overcharged battery.
To test charging system
To remove and install alternator
Regulator/Brush Assembly
To replace regulator brushes
321-1
321-2
321-2
321-3
field and begin the current generating process. This current is
provided by the battery through the alternator warning light in
the instrument cluster. If the lamp burns out, the alternator will
not charge the battery properly.
Charging System Quick-check
As a quick-check, measure the voltage across the battery
terminal with the key off and then again with the engine running. The battery voltage should be approximately 12.6 with
key oft and 14.0 with the engine running. If the voltage does
not increase when the engine is running, there is fault in the
charging system.
To test charging system
1. Inspect the V-belts and make sure they are tight. Make
sure the battery is fully charged, as described in 311
Battery.
2. Check the charge warning lamp. On 1987 and later
cars, check that the ignition switch relay closes when
the key is turned on. See 371 Wiring Diagrams, Fuses
and Relays for a complete listing of fuse and relay locations.
NOTE
• The charging system warning light should come on when the
key is on and go out when the car is started. Turning the key
on is a test that checks the warning light circuit to the alternator. If the light does not come on when the key is turned on,
check the light bulb and the wiring to the bulb using the appropriate wiring diagram before making any more tests. Wiring diagrams can be found in 371 Wiring Diagrams, Fuses and
Relays.
• When replacing the charging system warning bulb, be sure
to use the correct 2.0 watt replacement bulb. A similar 1.2 watt
bulb (with black socket base) will also fit in this location. If the
smaller bulb is installed, the battery will not charge correctly at
idle. The light will also go out at a higher rpm. See an authorized Saab parts department for additional information.
The alternator generates electrical current by electrical induction. When the engine is running, part of the current it produces energizes its electromagnetic 'field. When starting,
some other current must be provided to initially energize the
CHARGING SYSTEM TROUBLESHOOTING
Page 213
321-2
Alternator and Charging System
3. Check for battery voltage between ground and terminal
B+ at the back of the alternator. Then check for battery
voltage between terminal D+ and ground with the ignition key on.
NOTE
If the voltage is not present at either terminal, check the alternator wiring and electrical circuit using the appropriate wiring
diagram.
4. With the engine running, carefully measure the voltage
between terminal 0+ and ground and then between B+
and ground. The difference should not exceed 0.7
volts.
Fig. 1. Alternator mounting bolt being removed.
NOTE
If battery voltage was present at terminal D+ and B+ as described in step 3, but the voltage difference in step 4 is not as
specified, the altemator is faulty and should be replaced.
5. If no faults are found up to this point, the alternator
should be tested using special test equipment, such as
the Sun VAT40. Alternator test specifications are
shown below.
5. Install the new alternator, leaving the mounting bolts
slightly loose. Install the V-belt and tension it as described in 1 LUBRICATION AND MAINTENANCE.
CAUTION
V-belt tension is critical to the life of alternator and proper alternator operation. A loose belt will cause undercharging (and
often a loud screeching sound). A tight belt will quickly destroy
the alternator bearings and the bearings of other component
driven off the same belt.
Alternator output specifications
• Bosch 80 Amp
54 Amps @ 1900 rpm
6. Tighten all mounting bolts. Install the wiring to the alternator. Reconnect the battery terminal and check the
operation of the charging system warning lamp.
NOTE
If a load tester is not available, an output test can be done by
running the engine at 1900 rpm and turning on all electrical
loads such as fans, lights and heated window. Voltage at the
battery should be approximately 12 volts or higher.
To remove and install alternator
1. Disconnect the negative (-) battery cable.
2. Loosen the alternator mounting bolts, pivot the alternator and remove the alternator V-belts.
3. Disconnect the wires from the rear of the alternator.
4. Remove the alternator mounting bolts and the alternator. See Fig. 1
CHARGING SYSTEM TROUBLESHOOTING
NOTE
Be sure to reinstall the insulating boots to the wire terminals
on the back of the alternator.
Regulator/Brush Assembly
The voltage regulator is easily removed from the back of the
alternator by removing the two mounting screws. See Fig. 2.
The regulator is available as replacement part. In addition, the
carbon brushes can also be separately replaced.
With the regulator removed measure the brush length. See
Fig. 3. If the brush length is less than the minimum length specified in the figure, they should be replaced. Replacing the
brushes requires a soldering iron and electric/electronic solder.
Page 214
Alternator and Charging System
321-3
To replace regulator brushes
B
1. Remove the voltage regulator from the alternator.
2. Carefully unsolder the brush lead from the brush holder
terminal, withdrawing the brush from the holder at the
same time.
CAUTION
Wor!< quickly to prevent overheating the solid state regulator.
3. Remove any traces of solder from the brush holder terminal.
Fig. 2. Voltage regulator and brush holder removed from back of alternator. The brushes are at A, Remove the holder screws at B,
4. Fit the new brush into the holder, insert the brush lead
into the terminal, and solder it into place.
5. Reinstall the regulator.
......
5mm
87388-531513
Fig. 3.
Minimum regulator brush length, If brushes are shorter than 5
mm (0,2 in,), they should be replaced.
CHARGING SYSTEM TROUBLESHOOnNG
Page 215
Starter
331-1
TABLES
a. Battery, Starter and Charging System
Troubleshooting
331-2
331 Starter
Starting System
331-1
331-1
331-2
331-2
Starter Troubleshooting
To remove starter
To replace solenoid
replaced as an exchanged unit, the solenoid and other parts
are available from an authorized Saab dealer.
STARTING SYSTEM
The starter is an electric motor that drives a ring gear on the
flywheel via a pinion on the end of the starter. When the ignition key is turned to the start position, a solenoid moves the
pinion into engagement with the ring gear. The solenoid then
closes the main electrical contacts to the starter motor and the
motor turns to start the car.
When the engine has started, the ring gear speed exceeds
that of the pinion, and the pinion is disengaged from the pinion
shaft. When the key is released from the start position, a
spring returns the pinion to the rest position. Fig. 1 shows the
starter components.
The starter is located at the front of the engine under the intake manifold. The starter and solenoid are removed together
as an assembly. The solenoid can be separated from the
starter motor once removed. Althollgh the starter is generally
Starter Troubleshooting
Before troubleshooting the starter, make sure the battery is
fully charged and the battery cables and ground connections
are free of corrosion and in good condition. Troubleshooting
information forthe starting system appear in Table a.
NOTE
• For information on starter wiring and component location
see 371 Wiring Diagrams, Fuses and Relays.
• Starter efficiency is affected by engine oil viscosity. This is
especially true in cold weather. Make sure the correct oil is in
the engine. See 1 LUBRICATION AND MAINTENANCE.
13
14
15
~
~~~
I 2~21
12
I
19
22
16 1718
1
'-~
~8
9
87391·S3l248
10
2
1.
2.
3.
4.
5.
Starter bushing
Pinion housing
Circlip
Stop ring
Pinion bushing
6.
7.
8.
9.
10.
Starter pinion
Pinion engaging lever
Bearing bracket
Seal
Planetary gear train
11.
12.
13.
14.
15.
Armature
Solenoid
Stator frame
Brush holder assembly
Seal
16.
17.
18.
19.
20.
Seal
Commutator end bracket
Commutator end bushing
Seal
Shims
21. Spring washer
22. End cover
Fig. 1. Exploded view of starter motor.
STARTING SYSTEM
Page 216
331-2
Starter
Table a. Battery, Starter and Charging System Troubleshooting
Symptom
Probable cause
Corrective action
I
1. Starter does not
operate when
ignition switch is
turned to START
2. Starter tums slowly
or fails to tum
engine
a. Ignition switch or wire leading from
ignition switch to solenoid faulty (less
than 8 volts to solenoid switch)
a. Test for voltage at terminal 50 of solenoid switch with ignition
switch at START. If not at least 8 volts, test for voltage at terminal
50 of ignition switch with switch at START. Replace ignition
switch (See 432 Manual Transmission Control) or eliminate
open circuit between ignition switch and solenoid switch
b. Solenoid switch faulty (less than 8
volts to starter motor)
b. Test for voltage at field-winding strap with ignition at START. If
not at least 8 volts, replace solenoid
c. Starter motor faulty
c. Test for voltage at field-winding strap with ignition at START. If 8
volts or more, repair or replace starter motor
d. Automatic transmission neutral
safety switch faulty (models with
automatic transmission only)
d. Test switch. See 371 Wiring Diagrams, Fuses and Relays.
a. Dirty, loose, or corroded starter
connections
a. Remove, clean, and tighten connections
b. Dirty, loose, or corroded ground strap
between engine and body
c. Starter wom or faulty
3. Starter makes
unusual noise, tums
erratically, or fails to
tum
4. Starter operates,
but does not turn
engine
a. Drive pinion defective
b. Flywheel or driveplate ring gear
damaged
~
a. Starter drive pinion or annature shaft
I
I
faulty
b. Solenoid switch mechanism faulty
To remove starter
1. Disconnect the negative (-) battery cable. Remove any
hoses that may be in the way, such as the air intake
pipe.
2. Disconnect the large battery cable and the wire at terminal 50 from the starter motor.
NOTE
Tenninal 50 has a small wire leading into the tenninal. Tenninal 30 has a large cable coming from the battery. The fieldwinding strap is a braided wire running from the solenoid to
the starter housing.
See 364 Electric Controls and Switches for switch adjustment
I
I
I
b. Remove and clean or replace strap
I
i
~I
I
I
c. Repair or replace starter
a. Repair or replace starter
b. Replace flywheel or driveplate. See 216 Crankshaft
a. Repair or replace starter
b. Replace starter solenoid switch
3. Remove the solenoid retaining screws and withdraw
the solenoid, lifting it off the pinion engaging lever.
NOTE
The mounting screws are tightly fitted and may be difficult to
remove. To help loosen the screws, use an impact driver with
a slotted bit.
4. Install the new solenoid, hooking it over the pinion engaging lever. Make sure the terminals are correctly orientated and install the retaining screws and the fieldwinding strap.
5. Install the starter motor.
3. Remove the two bolts holding the starter to the engine
end plate and remove the starter.
Installation is the reverse of removal.
To replace solenoid
1. Remove the starter.
2. Remove the nut from the field-winding strap and disconnect the strap from the solenoid.
STARTlNG SYSTEM
Tightening torques
• field-winding strap and
battery cable to solenoid
• solenoid to starter
7-9 nm (62-80 in-Ib)
4.5-5.5 Nm (40-49 in-Ib)
Page 217
Ignition System
340-1
340 Ignition System
General
Basic Hall Ignition System
(1985 and later Turbo)
EZK Ignition System
(1986 and later Non-turbo)
EZK Knock Sensor Operation
and Ignition Timing
340-1
340-1
340-1
340-2
Ignition System Troubleshooting
340-2
On-board Diagnostics (EZK ignition only)
340-3
Test Equipment.
340-3
Disabling Ignition System
340-3
Basic Troubleshooting Principles
340-4
Quick-Check of Ignition System
340-4
Firing Order. . . . . . . . . . . . . . . . . . . . . . . . . . . 340-4
Visual Inspection
340-5
To test EZK ignition system
(non-turbo models only)
340-8
Component Removal
and Replacement
340-11
340-11
340-11
340-12
To replace distributor cap and rotor
To remove and install distributor
Hall Sensor
To replace Hall sensor
(distributor-mounted sensor)
To replace Hall sensor
(crankshaft-mounted sensor)
To replace knock sensor
(EZK ignition only)
340-12
340-13
340-14
Ignition Timing
340-15
340-15
To check and adjust ignition timing
Electrical Tests and Fault Tracing ... 340-5
To test basic Hall ignition system
(turbo models only)
TABLES
340-6
a. Ignition System Troubleshooting
340-5
GENERAL
Two versions of Hall-effect electronic ignition systems are
used on the cars covered by this manual. The term Hall-effect
refers to the Hall Sensor, an electronic device in the distributor
that replaces conventional mechanical breaker points.
Ignition System Applications
• 1985 and later Turbo ..... basic Hall-effect ignition
• 1986 and later Non-turbo. . . . . . . .. ElK ignitionHall-effect with knock sensor
87392-53003
1. Battery
2. Ignition switch
3. Ignition control unit
Basic Hall Ignition System
(1985 and later Turbo)
Fig. 1 shows a schematic of the basic Hall-effect ignition
system. The firing of the spark is triggered by the Hall sensor
in the distributor. The Hall sensor produces a voltage, which
provides the ignition control unit with information about engine
speed and crankshaft position. With this input, the control unit
operates the ignition coil secondary circuit to precisely time
the firing of the spark plugs.
4. Ignition distributor
5. Ignition coil
6. Shielded cable
Fig. 1. Schematic of basic Hall-effect ignition system,
EZK Ignition System
(1986 and later Non-Turbo)
Fig. 2 shows a schematic of the ElK ignition system. This
system is more sophisticated than the basic Hall system in
that it includes a knock sensor to monitor and control ignition
knock or ping. A knock sensor functions like a microphone
and is able to convert mechanical vibration (knock) into electrical signals. The ElK control unit is programmed to react to
GENERAL
:-:-:.:.:.:-:.;.:.;.:.:
iii
Page 218
340-2
Ignition System
the signals whose frequencies are characteristic of combustion chamber noise and change ignition timing accordingly.
EZK Knock Sensor Operation and Ignition
Timing
During cranking, the ignition timing is locked at 5°BTDC.
This setting will be held until engine speed exceeds 700 rpm.
The timing will then change to a fixed 14°BTDC setting until
the throttle is opened.
When the throttle is opened, the knock sensing system
takes over and adjusts ignition timing according to engine
conditions. The timing can vary from 5° to 22° BTDC in response to engine speed, engine load, or detonation. If engine
knock occurs, the ECU determines which cylinder(s) are
knocking and retards just the affected cylinder by 3°. If the
knocking continues, the timing is further retarded in steps of
3°. The timing position will be maintained for a short period
and will then begin to advance the timing by 1/3° increments
until normal ignition is resumed.
NOTE
An occasional knocking may be heard on engines with ElK.
This is normal and is necessary for proper operation of the
ElK system.
IGNITION SYSTEM TROUBLESHOOTING
87393
1.
2.
3.
4.
5.
6.
Battery
Ignition switch
Ignition coil
Distributor
Spark plug
ElK control unit
7.
8.
9.
10.
11.
Ignition amplifier
Hall sensor
LH control unit
Throttle position sensor
Knock sensor
Fig. 2. Schematic of EZK ignition system with knock sensor.
The throttle switch (also used in the LH fuel injection system) signals the ElK control unit when the engine is idling.
This allows the ElK control unit to set a base timing when the
throttle is closed. The ElK control unit also receives an "engine load signal" from the LH control unit.
NOTE
- For more information on the throttle switch, including adjusting and testing procedures, see 240 Fuel Injection.
- Turbo models also use a knock sensor to detect ignition
knock as part of the APC (Automatic Performance Control)
system. For more information, see 291 Turbocharger.
IGNITION SYSTEM TROUBLESHOOTING
Poor driveability may have a variety of causes. The fault
may lie with the ignition system, the fuel system, parts of the
emission control system, or a combination of the three. Because of the interrelated functions of these systems, it is often
difficult to know where to begin looking for problems. For this
reason, effective troubleshooting should always consider
these systems in unison, as one major system.
A complete failure of the ignition system to produce spark at
the spark plugs is self-evident. For other problems such as
rough idle, misfiring, or poor starting, however, the cause is
not so clear. For troubleshooting engine management and the
way the car runs, see 200 Engine-General.
Ignition system service and repair work must be carried out
carefully. The ignition system contains sensitive electronic
components. To protect the system, and for general safety,
the following warnings should be observed during any ignition
system troubleshooting, maintenance, or repair work.
WARNING
-The ignition systems installed on the cars covered by this
manual are high-energy systems operating in a dangerous
voltage range which could prove to be fatal if exposed terminals or live parts are contacted. Use extreme caution when
working on a vehicle with the ignition on or the engine running.
Page 219
Ignition System
WARNING
• Connect and disconnect ignition system wires, multiple connectors, and ignition test equipment leads only while the ignition is off. Do not touch or disconnect any of the high tension
cables from the coil, distributor, or spark plugs while the engine is running or being cranked by the starter.
• Before operating the starter without starting the engine (as
when making a compression test), always disable the ignition
as described below.
• Inefficient combustion can overload the catalytic converter
with raw fuel, leading to converter overheating or plugging. An
overheated catalytic converter can be a fire hazard.
340-3
On 1986-1991 models, start the engine and allow it to reach
operating temperature. Briefly raise engine speed above
2000 rpm. Count the number of times the check engine light
flashes before repeating the flashing code. The number of
times the Check Engine light flashes determines the fault in
the system.
EZK Check Engine light fault diagnosis
• three flashes-ElK control unit internal fault*
• four flashes - fault in the knock sensor, sensor wiring,
or ElK control unit
• five flashes - faulty input signal from LH control unit.
*This code is applicable to 1989 and later models only.
CAUTION
• Do not conduct ignition system tests with a test lamp that
uses a normal incandescent bulb. The high electrical consumption of these test lamps may damage the electronic components.
• Do not connect test instruments with a 12-volt supply to terminal15 (+) of the ignition coil. The voltage backflow can damage the ignition control unit.
• Do not connect terminal 1 of the coil to ground as a means
of preventing the engine from starting (for example, when installing or servicing anti-theft devices).
• Do not disconnect terminal 4 (center terminal) from the coil
or remove the distributor cap to disable the ignition.
• Do not disconnect the battery while the engine is running.
On-board Diagnostics (EZK ignition only)
The EZK ignition system features built-in diagnostic circuitry that detects and stores in memory coded information about
system faults. These fault codes can be "read-out" through
flashes of the Check Engine light. Before troubleshooting an
ElK fault and a flashing Check Engine light, check for broken
or loose engine mounts or brackets.
NOTE
• As a general rule, a steady-on Check Engine light means the
LH control unit has detected a fault. A flashing Check Engine
light means that the ElK Ignition system has detected a fault.
As an exception to the rule, the Check Engine light on 1992
models does not flash. Therefore, a steady-on Check Engine
light on these models could be either a ElK system fault or an
LH fuel system fault.
• On 1989 models with ElK only, the Check Engine light may
flash intermittently due to a faulty ElK control unit. Check for
a control unit date code of "945" or lower (see Fig. 13 for control unit location). The date code is stamped on the unit next
to the connector housing. If the control unit is within these
dates codes, see an authorized Saab dealer for additional information on correcting this fault.
NOTE
If the wiring harness to the ElK knock sensor is defective, a
replacement wire harness is available from an authorized
Saab dealer. This harness eliminates the need to replace the
entire engine harness.
Test Equipment
Many of the tests of ignition system components require the
use of high-impedance test equipment to prevent damage to
the electrical components. A high-impedance digital multimeter should be used for all voltage and resistance tests. An LED
test light should be used in place of an incandescent-type test
lamp.
Many tests require checking for voltage, continuity, or resistance at the terminals of the components' harness connectors. The blunt tips of a multimeter's probes can spread open
the small connector terminals and cause poor connections.
To prevent damage, use flat male connectors to probe the
harness connector terminals.
Disabling Ignition System
To prevent the engine 'from starting and to prevent the presence of dangerous voltages, the ignition system should be
disabled anytime work is done on the ignition system. The ignition system should also be disabled any time work is being
done in the engine compartment with the ignition key on or if
the starter needs to be operated without running the engine,
such as when making an engine compression test.
Disabling the ignition system is easily accomplished by disconnecting the Hall sensor connector. On all 1985-1988 models and 1989 and later Turbo models, disconnect the Hall
sensor connector from the side of the distributor. On 1989 and
later models with ElK ignition, the Hall sensor is mounted behind the crankshaft pulley. To disconnect the sensor connector, follow the wiring harness up from the sensor until you
reach the connector in the engine compartment. See Fig. 3.
IGNITION SYSTEM TROUBLESHOOTING
Page 220
340-4
Ignition System
To make the check, turn the ignition off and remove a spark
plug wire from a spark plug. Connect to the plug wire a sparktester or a known good spark plug gapped to 4 mm (0.16 or
5/32 in.) Position the plug so that the outer electrode is
grounded on the engine.
NOTE
For the most accurate test results, the battery should be fully
charged.
Fig. 3. Hall sensor connector on 1989 and later cars with EZK ignition. The sensor on these cars is mounted behind crankshaft
pUlley.
Basic Troubleshooting Principles
An engine that starts and runs indicates that the ignition
system is fundamentally working-delivering voltage to the
spark plugs. A hard-starting or poor-running engine, however,
may indicate a problem with how well the spark is delivered. A
faulty coil or control unit, cracked or deteriorated spark plug
wires, a worn or cracked distributor cap or rotor, and worn or
fouled spark plugs are all causes of reduced spark intensity
and inefficient combustion.
An engine that has good cranking speed but will not start
may indicate a complete failure of the system to produce
spark. Inspect the ignition system visually. Make sure the
spark plug wires have not been interchanged. Ignition firing
order is described below under Firing Order.
If no visual faults are located, maKe a basic quick-check to
see if spark is being produced as described below. This will be
the most important first troubleshooting step. If a strong spark
is observed, then the failure to start is due to another cause,
perhaps no fuel being delivered to the engine.
Quick-Check of Ignition System
The first step in troubleshooting a no-start condition is to determine whether the problem is caused by the ignition system
or some other system, such as a fuel delivery problem. This
done by checking that the spark plugs are firing. If no spark is
present, then more detailed testing of the ignition system is
necessary.
IGNITION SYSTEM TROUBLESHOOTING
While a helper actuates the starter, look and listen for spark
in the spark plug gap. A bright blue spark Indicates a healthy
ignition system. A yellow-orange spark is weaker and indicates
that, while spark is present and the system is functioning, it is
not operating at peak efficiency. Check the condition of the ignition system components as described below Visuallnspection. If there is no spark, test the system components as
described below under Electrical Tests and Fault Tracing.
WARNING
• Do not hold the spark plug or its connector, even if using insulated pliers.
• If ignition system failure is not the problem, the engine may
start during this test. Be prepared to tum off the ignition immediately. Running the engine with a spark plug wire disconnected may damage the catalytic converter.
If no faults have been detected up to this point but there is
still no spark or a weak spark, refer to Table a for more troubleshooting information. If a strong spark is observed but the
engine still will not start, refer to 200 Engine-General for
more troubleshooting information.
Firing Order
The firing order of the cylinders is 1-3-4-2. Cylinder no. 1 is
next to the V-belts by the firewall and cylinder no. 4 is at the
front of the car. The engine rotates counter-clockwise when
viewed from the front of the car. See Fig. 4.