1990 MITSUBISHI ECLIPSE ignition

q7 --_-.-ENGINE
- General Information9-3TECHNICAL FEATURES
HIGH PERFORMANCE AND . . .._..............1. The DOHC 16-valve engine ensures excellent intake and exhaust
FUEL ECONOMYefficiency.
2. The rocker arm is of the roller-type-cam-follower design which Iminimizes friction loss.
3. The combustion chamber is of the pentroof type with a squish
area that offers outstanding combustion efficiency.
4. The multipoint fuel injection system is electronically
controlled.5. The intake manifold is the inertia supercharging type which
improves intake efficiency and the dual-type exhaust manifold
offers good exhaust efficiency.
6. The two-coil type electronic control ignition system ensures
good ignition performance.
LOW VIBRATION AND. . . . . . ..I.................1. The hydraulic lash adjuster, together with the roller rocker arm,
LOW NOISEcontributes to reduced operating noise of the valve mechanism.
2. A cogged type belt is used to drive the camshaft.
3. The auto tensioner maintains the optimum timing belt tension.
4. The torsional damper reduces twisting vibration in the crankshaft’
to a minimum.
5. The silent shaft system reduces engine vibration and rolling
’moment to a minimum
SERVICEABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1. The self-diagnosis system makes troubleshooting easier.
2. The lash adjuster eliminates the need for valve clearance
adjustment.3. The auto tensioner eliminates the need for timing belt
tension adjustment.
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14-1
FUEL
RWA---
ACCELERATOR COMPONENTS
.72
Auto-cruise Control Switch
:.............. 77
Self-diagnosis and Input-check Functions
injector................................................................34
PRESSURi
CONTROL ............................................................
31
Fuel Tank............................................................i
injector................................................................
Specifications
izi
INTAKE
il
Coolant Temperature Sensor
;iI
General Description
: .................... 24
ignition Timing Adjustment Terminal ............
CA/T>.................................... 26
i:
..........
.-.---__-...- -.---.

sors and the engine control unit, tooether with
actuators and
related components, and k controlled
according to nine control functions as shown below.
Of these nine, No.
1 and, Nos. 3 to 9 are supplied by
II
EngineSensors - control -unit
r--------‘-1
l--cIFuel-pressureIcontrol valveII
‘4 Fuel DumoI13 I I or-’I
,--c 1. ;;EILT!I;ELSSURE1J
Fuel presJ1regulatorI
- Throttle valve
i
7
_c Speed adjusting
screw
14-2
“GENERALFUEL SYSTEM
- GeneralRl484AB
The fuel system is of the Electronic Control
Multi-point Fuel Injection type, which has an injector forthe engine control unit.
each cylinder. The system comprises various sen-Refer to Group 8 ELECTRICAL for No. 6 IGNITION
TIMING CONTROL.
-Fast idle air valve
- idle speed
control servo-
IrI
- Injectors
- 4. IOLESPEEO
CONTROL
-I5. POWER SUPPLYCONTROLControl relay
-) 6. V$&iRq3NLTIMING- Power transistor
b
-c 7. AIR CONDITIONERRELAY CONTROL- Air conditioner
relay
c-------------Tp----------1
NOTEI
The [‘-,l> is applicable to theI
.-( 8. ZJJ\~RR~LARGING k-- -4 Wastepate
Liturbo only.-----w--------IL solenoid valve--B--------d
Ir-‘---‘---“‘-7c------v--w-1
L’ 9.
-I
‘C;RB;zLETER--A Turbo meterI--------c----J+ L----------a
k’6FU1145

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

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.- -_-_
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.

14-18FUEL SYSTEM - Sensors
tBAROMETRIC PRESSURE SENSOR
Barometnc rxessure sensor
EC1537
Barometncpressure sensor
Enginecontrol unit
1OFUO576
/
760 (30)Barometric pressure mmHg
(in.Hg)EC1551A barometric pressure sensor is
alas mounted on
the
aif flow sensor. It senses the barometric
pressure and converts it to electrical voltage which
is sent as a signal to the engine control unit.
Using this signal, the engine control unit calculates
the altitude
of.the location where the vehicle is, and
corrects the fuel injection quantity for the optimum
air-fuel ratio at that altitude, and also corrects the
COOLANT TEMPERATURE SENSOR
Terminal 26EL0069ignition timing.
This ensures improved driveability at high altitudes.
The barometric pressure sensor converts the pres-
sure to a voltage making use of the fact that the
resistance of a strain gauge changes in direct
proportion to the pressure as shown in this diagram
which
illustratestherelationship between
barometric pressure and output voltage.
Engine control unit
Coolanttemperature
sensor
-a
Tg-I
h-esI
*
5 volts
LizIdr
tSFUOLSL
L0 (32120 (68)Coolant temperature -The engine coolant temperature sensor installed in
the coolant passage of the thermostat case is a
thermistor whose resistance changes with the
engine coolant temperature.
The
annine control unit iudoes the enoine warm UDstate based on the output voltage of this sensor and
provides optimum mixture enrichment when the
engine is cold.
The sensor characteristics are as shown above..:I

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,
14-24FUEL SYSTEM - Sensors
POWER STEERING OIL PRESSURE SWITCHEngine control unit
Power steering oil
pressure switchBattery
voltage
6FUO5OtIWhen the steering wheel is turned and the oil
pressure of the power steering oil pump increases,
the power steering oifpressure switch sends an ON
signal to the engine control unit. The engine control
unit detects the oil pump load with this signal andactivates the idle speed control servo to control
theidle speed. Specifically, it prevents the idle
speecfrom dropping due to oil pump load, thus
ensuringstable engine idling.IGNITION
SWITCH
1IBattery
Ignition
switch
Starter motor
aS terminalcontrol unit
6FUO762The signal indicating that the ignition switch is ON,
OFF or cranking (ST) is input to the engine control
unit.
When the ignition switch ON signal is input to the
engine control unit, the unit energizes the control
relay coil to supply power to the sensors and
actuators.When the ignition switch ST signal is input to the
engine control unit, it determines that the engine
iscranking and controls the fuel injection rate,
despeed control servo, ignition timing, etc. for
-mum cranking conditions.