1990 MITSUBISHI ECLIPSE oil temperature

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.
--. .----- ---- --- ___. .-. ___.,.__

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.
-
. .1-_ .---

9-18ENGINE- Base Engine
(1) The intake camshaft, exhaust camshaft, and the
oil pump are driven by a single timing belt.
(2) Timing belt tension varies at different engine
temperatures and ages of the belt. The autotensioner absorbs these changes in belt
ten+n,not only to prevent the noise problem
getting worse, but to improve durability as weli’l
AUTO TENSIONER
Piston -1
Check ball-4,
SpringTensioner
cwllev
6EN0116
LOoil seal
6ENOWThe auto tensioner applies tension to the timing belt
by causing the tensioner arm to move back and
forth in the directions shown by arrow
@I.The bottom figure shows the construction of the
aUt0 tensioner. The chambers on the right and leftof the piston
are filled with silicone oil.
Both the tensioner pulley and idler pulley are of the
ball bearing type into which grease has been
packed.

FUEL SYSTEM - General14-3The fuel is supplied under pressure by the in-tanksent to the engine control unit.
type fuel pump, and is injected from injectors into allThe crank angle sensor converts the crank
angle,
cders. The injectors are activated by signals fromthat is, engine turning state into an electric signal
tk, engine control unit, and the amount of fueland sends it to the engine control unit.
injected is determined according to the drivingThe engine control unit, based on these signals,
conditions.determines the basic activation timing of the
injec-The intake air passes through the air flow sensor,
tars. The amount of intake air is determined by the
throttle body, air intake plenum and intake manifold,degree of opening of the throttle
valye,, and during
and finally enters the combustion chamber. The airengine idling, the amount of intake
arr IS regulated
flow sensor detects the amount of air flow and
by the idle speed control servo.converts this data to electric pulse signals that are
EGR temperature sensor (California) 7
Waste gate solenoid valve
Purge control solenoid valve
EGR control solenoid valve Fuel pump relay
Control relay
Air conditioner relay
Diagnosis output
Ignition coil
Control relay (Fuel pump drive
signal)Vehicle speed
SensorIgnition switch “ST” terminal
Ignition switch
‘IG” terminal
Air conditioner switch
Power steering
switch
Inhibitor switch
Idle speed
ontrol servoFast idle
air valve
-Throttle
&r -kilo m-i&inn’Power transistorleturn to-
uel tank- Fuel from
Coolant temperature sensor
Coolant temperature switchFuel-pressure
control valve
Detonation sensor
4

14-6FUEL SYSTEM -Fuel Supply and Fuel Pressure Control
intake manifold/I\
Engine
Fuel
03AOOlOThe fuel supply system comprises electromagnetic
type injectors, a delivery pipe, a fuel pressure
regulator, a motor-driven fuel pump, and the engine
control unit, which activates and controls the injec-
tors and fuel pump based on data supplied by the
various sensors.
After being filtered by an in-tank filter, the fuel is
pumped from the tank and is filtered again by an
external filter before it is distributed to the injectors
through the delivery pipe. The pressure of fuel
delivered to the injectors is regulated by the fuel
pressure
reoulator; excess fuel after pressure reg-ulation has been performed is returned to the fuel
tankThe injectors are activated on command from the
engine control unit and inject the fuel to each intake
port of cylinder head sequentially according to the
predetermined ignition order.
In addition, a fuel-pressure control valve has been
equipped in order to maintain idling stability of turbo
models immediately after restarting under high- -
temperature conditions.
The fuel tank is located under the floor of the rear
seat, thus giving it protection in the event of a
rear-end collision. A fuel pump drive terminal is
provided in the engine compartment for greater
serviceability.
-
SPECIFICATIONSItems
Fuel pump
Type
Delivery rate
liters (gals.VHr
Delivery pressurekPa (psi)
Fuel pressure regulator
Tvw
Regulated fuel pressurekPa (psi)
Fuel filter
Rated flow rate
liters (qts.)/min.
Filter areacm’ (in.‘)
Injectors
TypeCoil resistance
n

--
.- -_-_
SpecificationsMotor-driven, in-tank type
Minimum 90 (23.8)
450 - 600 (64 - 85)
Diaphragm type
335 (47.6)
255 (36.3)
2
(2.1)
1,500 (233)Solenoid type
,.13-16
2-3
I

14-14
.._~- ---.FUEL SYSTEM
- Sensors
SENSORSRlUGENERAL DESCRIPTION
The types and functions of the sensors are as listedsend corresponding signals to the engine control
below. These sensors detect engine conditions and
unit.
SENSORSFUNCTION
AIR FLOW SENSOR
fSenses the intake arr volume with a Karman vortex flow meter.
INTAKE AIR TEMPERATURE
SENSORSenses the Intake air temperature (temperature of air at
the point of entry into the air cleaner).I
BAROMETRIC PRESSURE
SENSORISenses the barometric pressure faltrtude) wrth a
semiconductor diffusion type pressure sensor.
$;;OOf;T TEMPERATURESenses the engine coolant tern
THROTTLE
POSITISenses the throttle
tI
IDLE POSITION SWITCHSenses whether or not the accelerator pedal is being
operated with a contact switch.
Senses the top dead center on compression stroke of
NO. 1 and No. 4 cylinders with an LED and photo diode pair.
CRANK ANGLE SENSORSenses the crank angle of each cylinder with an LED
and photo diodepair.
T
OXYGEN SENSORSenses
actrvation of the air con
POWER STEERING OIL
PRESSURE SWITCHc-lSenses the power steering ‘load with a contact switch.
IGNITION SWITCHSenses ON/OFF
posrtion of the ignition switch.I
Senses engine cranking.
,
IGNITION TIMING
ADJUSTMENT TERMINALWhen this terminal is shorted, the ignition timing and idle
speed control servo is set in the adjustrng mode by the enginecontrol unit.
INHIBITOR SWITCHSenses the *P” and “N” positthe automatic transaxle.Senses.
by pieto-electric element,. cylinder block
vibrations that occur when there ISengineknocking.
CONTROL RELAY
(Fuel pump drive signal)
lFnorne ianitron sianal!Senses ignrtton coil prIman/ voltage.

FUEL SYSTEM- Engine Control Unit14-29
SFUllSOTerminal
ConnectionTerminalConnectionNo.
No.
1Self-diagnosis output53EGR control solenoid valve (California only)
2Diagnosis/data transfer select terminal54Power transrstor for No. 1 and No. 4 cylinder
‘3Turbo meter
55Power transistor for No. 2 and No. 3 cylinder
4Oxygen sensor56Control relay (Fuel pump control)
5Power steering oil pressure switchl 57Fuel-pressure control valve
6Idle position switch58Coil “Al ” for idle speed control servo
7Air conditioner switch59Coil “A2” for idle speed control servo
8Intake air temperature sensor60No. 3 injector
l 9Detonation sensor61No. 4 injector
10Air flow sensor62Purge control solenoid valve11
-63Control relay
12Ignition timing adjustment connector64Engine warning irght (Malfunction indicator light)
13Control relay (Fuel pump drive signal)65Air conditioner relay
l 14Air flow sensor active filter reset66Control relay
15EGR temperature sensor (California only)67Coil “Bl ” for idle speed control servo
16Barometric pressure sensor68Coil “B2” for idle speed control servo
17Sensors ground101Ground
18Vehicle speed sensor102Power supply
19Throttle position sensor103Power supply for backup
20Coolant temperature sensor
104Inhibitor switch
21Crank angle sensor‘105
Waste gate solenoid valve
22Top dead center sensor106Ground
23Power supply for sensors (5 volts)107Power supply
24Sensors ground108“ST” terminal for ignition switch
51No. 1 injector109Ignition pulse detect
52No. 2 injector170“IG ” terminal for ignition switch
NOTETerminals indicated by the l symbol are applicable only to turbo models.

14-30SELF-DIAGNOSISFUEL SYSTEM- Engine Control Unit
There are 16 diagnosis items, as listed below; the
diagnosis results are stored in computer memory.The diagnosis memory is maintained by backup
The stored results can be ready by connecting apower from the battery (not by way of the ignition
circuit tester or voltmeter to the diagnosis
connec-switch) so that it will not be lost even if the ignition
switch is turned OFF.
tor.
DiagnosisOutput pattern
codeEl
None
lP
@ 11l-l
@ 12n@ 13
@ 14
@ 21Ul n
Diagnosis items
Faulty computer in the engine control unitMalfunction of the air/fuel ratio control system
Open or short circuit in the oxygen sensor circuit
Open or short circuit in the air flow sensor circuit
Open or short circuit in the intake air temperature sensor
circuit
Open or short circuit in the throttle position sensor circuit
Open or short circuit in the engine coolant temperature sensor
circuit
022u1 nn
No voltage change of the crank angle sensor signal
,
@
23
u u-inn
No voltage change of the TDC sensor signal
24uu-uvinnnnNo voltage change of the vehicle speed sensor signal
Q25uuuuuunnnnnOpen or short circuit in the barometric pressure sensor
2 31I-~-~---~ nOpen circuit in the detonation sensor circuit
@ 41uuul nOpen circuit in the injection circuit
042UUuLJul
Malfunction of the control relayOpen or short circuit in the fuel pump drive circuit
z 43UUULnlulMalfunction of the
EGR system
Open or short circuit in the EGR temperature sensor circuit
%4u u u uvinnOpen circuit in either of ignition coil circuit
0nNormal (with none of above faults)
. IA-r-NUltl 1: l 2: for California@ denotes items indicated by an illuminated engine warning light