engine MITSUBISHI ECLIPSE 1990 Owner's Manual

. . .&L : __,ELECTRICAL
- Inspection Terminal
INSPECTION TERMINAL
INameSymbolNameEngine speed detecting terminal
COxygen sensor check connector
Fuel pump check connectorASelf-diagnosis connectorIgnition timing adjustment connector
B -
NOTEThe “Name” column is arranged in alphabetical order.
Symbol
D
E16Ao734

ELECTRICAL- Ermine Electrical8-23
ENGINE ELECTRICALRoaGAABALTERNATOR
L terminal\Stern
Electronicvoltage regulator
B terminal/
Rectlfber‘i ‘IT
VFantl
GEL0051The alternator has a built-in electronic voltage regulator.
The output voltage is controlled by the voltage regulator
through detection of the battery voltage.
SPECIFICATIONS
Nominal output . . .._...._..65A: for Non-turbo Engine with M/T
75A: for Non-turbo Engine with AAand Turbo Engine
Regulated voltage. . . . . . . .14.4 f 0.3V at 20°C (68°F)
Rotating direction. . . . . . . .Clockwise(viewed from pulley side)
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.-
8-24ELECTRICAL- Engine Electrical
STARTER MOTOR
Reduction gearMagnetic switch
S terminal
Shift lever
6ELOO53
!n
IArmature
1Pinion gearOverrunnIng
hlclutch -Permanent magnet
6EL0055
SPECIFICATIONS
Type................................Reductiondrive
Nominal output
............1.2 kWRotating direction
........Clockwise
(viewed from pinion side)
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IGNITION SYSTEMELECTRICAL - Engine Electrical8-25
I
Sensors
Engine control unitlgnltlon switch
Battery
11 IPower transfstor
hhP 1
Ilgnltion coil
C To tachometerTerminal for engine
speed detectton
6ELOO45The ignition system is a two-coil ignition system that
supplies sufficient energy for ignition up to high
speeds. This engine does not have a distributor
since the engine control unit directly activates the
power transistor for ignition timing control.
The functions and controls of the engine control unit
and various sensors that control the ignition timing
are described in the next chapter, IGNITION CON-
TROL SYSTEM.
This ignition system has two power transistors and
two ignition coils. Power transistor “A” controls the
primary current of ignition coil “A” to activate thespark plugs of the
No.1 and No.4 cylinders.
Similarly, power transistor
“B” controls ignition coil
“B” which activates the spark plugs of the
No.2 and
No.3 cylinders. In this way, spark plugs of two
cylinders are activated but actual ignition takes placeonly in the single cylinder that is on its compression
stroke, because the other is on its exhaust stroke at
that time.
Power transistors “A” and “B” are activated by
signals from the engine control unit, that controls
which cylinder is fired at what time.

8-26ELECTRICAL - Engine Electrical
No.:
4Signal unit for
, tachometer
71
x
No. 3
6EL0025
Capa &orCylinderNo. mark
6EL0057
To No. 1spark plug
To No. 4
spark plug
To No. 3spark plug
To No. 2spark plug
6EL005t
OC,IB, G
OC, IB, G IB, OC:IGNITION COIL
Two compact ignition coils of a molded type featuring
outstanding ignition performance are used.
Being a two-coil type, the ignition coil has a unit to supply
signals for the tachometer.
Specifications
itemsSpecificationsPrimary coil resistance
$20.86 at 20°C (68°F)
Secondary coil resistance
kR12.1 at 20°C (68°F)POWER TRANSISTOR
The power transistor is driven by a signal from the engine
control unit and turns the priman/ current of the ignition coil on
and off.
Terminal symbol
External connection
G
IB,
I&
Ground
Engine control unitEngine control unit
OGoc2Ignition coil terminal “2”
Ignition coil terminal “1”
SPARK PLUG
IEngineTypeGapI-
Non-turboBPR6ES-11WZOEPR-11RN9YC4
1.0-1.1 mm(.?39-.043 in.)I
0.7-0.8 mm(.OZB-.031 in.)A

-----. _-- ___ELECTRICAL
- Engine Electrical8-27IGNITION TIMING CONTROL SYSTEM
Air flow sensor
Engtne control unit
Intake air temp. sensor
Barometric pressure sensor
Engine coolant temp. sensorIdle position switch
:+
Top dead center sensor
Crank angle sensorVehicle speed sensor
;+Ignition switch “ST” terminal
Detonation sensor for
turbo engine only
Battev
4 Power= tranststor “B”P Ignition coil
109
_
I
1
12a”- To tachometer
Terminal for engine speed detection
Terminal for ignition,timing
and idle speed adjustment
6FUoE.45The ignition control system uses the engine control
consideration the operating conditions of the
en-unit, that judges which cylinder is to be fired at what
gine. The functions and controls of the engine
time based on the signals coming from variouscontrol unit are described in the following page.
sensors. The engine control unit activates the
The constructions and functions of the various
power transistors so that ignition occurs, taking into
sensors are described in GROUP 14.

8-28ELECTRICAL- Engine Electrical
IGNITION TIMING CONTROL
Reading of Input signallgnitlon power
distribution control
(selection of power
transistor actlvatlon)Control mode
I II II IControl mode
dectsion data
Basic energlzatlon
I’
Engine control unitPower
Powertranststor “A”tranststor “B”
6ELOO66The above block diagram shows the
fljnctions of the
engine control unit for ignition timing control.
One feature is that the engine control unit provides
ignition power distribution control which is neces-
sary because this engine is without a distributor, as
has been described earlier. By activating two power
transistors alternately, the primary current of two
ignition coils, one for the No. 1 and No.4 cylinders
and one for the No. 2 and No, 3 cylinders is turned onand
off. thus causing the cylinders to fire in the
order of 1, 3, 4, 2.
For ignition timing control, -optimum ignition timing.^--_
_. -.is determined by making preset corrections which
has been for engine coolant temperature, intake air
temperature an& other conditions of the ignition
advance angle that has been preset according to the
engine operating conditions. For vehicles with
tur=_.bocharger have a knocking control that corrects tl
ignition advance angle according to the presence or
absence of knocking.
The engine control unit also controls the primary
current energization time in order to secure stable
ignition energy.
These controls are explained in detail below.
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. ,-s- ,-T,“~:~y.“‘~...:tg==ELECTRICAL
-Engine Electrical8-29Ignition Power Distribution Control
No. 1 TDC
I
No. 3 TDCNo 4TDCNo 2 TDC
‘op dead center signal,\
I1IIII
Crank angle signal
No. 1 cylinderCombustionExhaustIntakeCompres-
strokestrokestrokeslon stroke
IntakeCompression
t\
CombustionExhaust
No. 3 cyltnderstrokestroke. strokestroke
No. 4 cylinder, t\
IntakeCompressionstrokestroker$,mkbeustlonExhauststroke
Combus-No. 2 cylinder tlon
strokeintake
strokeCompresslon
stroke6EL0067
75”BTDC TI
Crank 1
f Time count start6EL217The cylinder to be ignited is determined based on the top dead
center signal and the crank angle signal.
If the top dead center signal has already been input to the
engine control unit when the crank angle signal is input, the
unit decides that the No. 1 cylinder (or No. 4) cylinder is on the
compression stroke and turns off power transistor “A” and
causes the No. 1 cylinder (and No.4 cylinder) to fire.
If the top dead center signal has not been input to the engine
control unit when the crank angle signal is input, the unit
decides that the No.3 cylinder (or No. 2) cylinder is on the
compression stroke and turns off power transistor “B” and
causes the No.3 cylinder (and No. 2 cylinder) to fire. In this way,the power transistors “A” and
“B” are turned off alternately for
ignition power distribution.t
= T/180Once
t is determined, the ignition timing (T,) is calculated using
the t value and the ignition advance angle (advance from
TDC)determined by the engine control unit, with the
75”BTDC Signal
as a reference; then the primary current shut-off signal
is Sent
to the power transistor when
T, time has elapsed from the
count start position
(75“BTDC).Tl= t
x (75 - 9)
where 8 is the ignition advance angle calculated by the engine_, ~4 -‘*Lonrrol unlr.Ignition Timing Control
The period
(T) of the crank angle signal is measured and based
on this
v&lue, the time (t) taken for the crank to make a
revolution is determined.

8-30ELECTRICAL - Engine Electrical
Ignition Advance Angle Control
While
cranking
Fixed angle(5”BTD.C)Engme coolantBarometnc‘-Intake air 1temperaturepressuretemperaturesensorsensor, sensor
Dunng normal operatlon4i+
Advance angle map valueEngine
coolantBarometricIntake airaccording to engine speed4and intake air volumetemperature- pressure__c temperature 4
correctioncorrectloncorrectton
Durtng ignition tlmmg adjustment
Fixed angle(5”BTDC)
c
=ower transistor
-$To ignition
coil
s
6EL0066The engine control unit has the ignition advance
angle value for all cylinder stroke intake air volumes
(engine load) and engine speeds stored in its
memory; this is called the basic ignition advance
angle. The control unit makes corrections in this
value according to the engine operating conditions
such as the engine coolant temperature, barometric
pressure (altitude) and intake air temperature to
obtain optimum advance angle for current engine
conditions. At the engine start and during ignition
timing adjustment, however, it is set to preset fixed
timing.
(1) WHILE CRANKING
When cranking, the ignition advance angle is fixed at
5”BTDC in synchronization with the crank angle
signal.(2) DURING NORMAL OPERATION
Basic ignition advance angle:
Map values that have been preset for all cylinder
stroke intake air volumes (engine load) and engine
speeds.Engine coolant temperature correction:
The engine coolant temperature sensor detects the
engine coolant temperature and when it is low, the
-ignition timing is advanced to improve driveability.
Barometric pressure correction:
The barometric pressure sensor detects the
barometric pressure and determines the altitude.
When the pressure is low (i.e. when the vehicle is at
a high altitude), the ignition timing is advanced to
secure maximum driveability.
intake air temperature correction:
The intake air temperature sensor detects the intake
air temperature and when it is low, the ignition
timing is delayed to prevent knocking in cold
weather. When it is high, the timing is also delayed
to prevent of knocking.
(3) DURING ADJUSTMENT OF IGNITION TIMING
When the terminal for ignition timing and idle speed
adjustment is shorted to ground, the ignition timing
is set at
5”BTDC in synchronization with the crank
angle signal, If the ignition timing does not agree
with the reference ignition timing of 5’BTDC, turn
the crank angle sensor to adjust the timing so that
the crank angle signal agrees with the reference
ignition timing. When the engine speed is approx-
imately 1,200 rpm or higher, however, the timing
advance is according to normal operation and
therefore this ignition timing adjustment is not
available.
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. .1-_ .---

Knocking Control for Turbo Engine OnlyEngine coolant tern.Advance mapperarure correctton
value- Barometric pressurecorrectton
DelonaIlon
sensorI
lgnmon codKnockmg correcllonprimary currenr
v
Knock wbral+onKnockmg LevelDelay anglelgnmon tlmtngdetemon- delermonmon - calculallon - derermmatlon
II
Y
FatlureIdeIeclton
6FUO565Engine knocking is detected and the ignition timing
is controlled accordingly to prevent continued
knocking and to protect the engine.
When knocking is detected, the engine control unit
delays the ignition timing according to the signal
from the detonation sensor until the knocking is
eliminated (up to a maximum 12” in crank angle). In
the case of an open or short circuit of the detonationsensor harness. the timing is delayed by a fixed
angle (approximately 8” in crank angle) to prevent
knocking.Energization Time Control
While
crankinaIf knocking continues, the advance angle map value
is corrected gradually in the delay direction.
In the absence of knocking, the map value is
corrected gradually in the advance direction. In this
way, optimum ignition timing is constantly control-
led; this control is effective even when fuels of
different octane ratings are used.
This means that the engine is protected from
knocking damage even when the fuel is switched
from premium to regular or vice versa.
Synchronizedwith crank angle
sensor signalcDuring normal operation
Map value
cor-Energizatlon time
responding to- is clipped at 75% of
battery voltageignition interval
IIn order to obtain stable ignition energy, the
ener-gization time of the ignition coil primary current is
controlled as to keep current at a constant value
when the primary current is shut off.
(1) DURING NORMAL OPERATION
Basic energization time
:The increase of the ignition coil primary current
changes with the battery voltage. Therefore, the
energization time is so controlled that the primary
current at time of ignition becomes
6A. The basic
energization time is so set that it is longer when the
battery voltage is low and is shorter when the
6FUO548Energization time clip:
The new two-coil ignition system has its ignition
interval doubled when compared to the convention-
al single
coil type, allowing a longer clip time. As a
result, a long energization time is secured for
sufficient ignition energy even during high speed
operation.
(2) WHILE CRANKING
When cranking, the ignition coil is energized in
synchronization with the crank angle signal.
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