1990 MITSUBISHI ECLIPSE engine

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.

,_-.._-~_._. I _ ‘... ----
ENGINE- Base Engine9-19
Reservoir
chamber/
Reservoir
chamber
PressurechamberOperation of the Auto Tensioner
WHEN THE BELT TENSION HAS INCREASED
(1) The tensioner arm pushes the piston in the direction shown
by
arrow @, causing the hydraulic pressure in the pressurechamber to build up.
(2) The check ball closes.
(3) The oil inthepressure chamber is compressed by the
piston, which causes a small amount of oil to gradually leak
through the clearance between the piston and cylinder into
the reservoir chamber. This causes the piston to move
slowly in the direction shown by arrow
@.
(4) The piston stops moving when the load in the direction @balances the spring tension, which determines the load,
i.e., tension, applied to the belt.
WHEN THE BELT TENSION HAS DECREASED
(1) The piston moves in the direction shown by arrow @I by the
spring tension.
(2) As the piston moves, the hydraulic pressure in the pressure
chamber becomes lower than that in the reservoir cham-
ber.
(3) The check ball opens.
(41 Oil enters the pressure chamber.
(5) The piston stops moving when the belt tension balances
the spring tension, which determines the tension applied to
the belt.
_ . _ ---___- -

9-20ENGINE- Lubricathn System
LUBRICATION SYSTEM
nasllOil cooler*
r-4--I-
(oil pressure regulator)
I
n I-1Oil filter
pressureswttch
NOTE
l
: Turbo6LUOO43The lubrication system is the pressure-feed, full-
flow filter system. The engine oil sent under
pressure by the gear-type oil pump is filteredthrough the cartridge-type oil filter before being
delivered to the various engine parts.
SPECIFICATIONS
ItemsOil pump
Type
Delivery rate
Relief valve opening pressure
Oil pressure switch
Type
ON pressureOil filter
Specifications
Gear type
10 cm” (.Sl cu.in.)/engine revolution
550 kPa (78 psi) or more
Contact-point type
30 kPa (4.3 psi) or less
Cartridge type

L1ENGINE
- Mounts9-21MOUNTS
Rost3u
. *the mounts, the principal axis of inertia support
system is employed.
This principal axis of inertia support system of
mounting functions to support the upper
part of the
engine and the upper part of the transaxle, thereby
effectively suppressing engine vibrations. Note that
there are the following features at the various
installation parts.
lThe transmission of engine vibration to the body
is reduced by the installation, via bushings, of
the centermember to the body.
lThe insulators each have a cavity that serves to
effectively absorb vibrations.
CONSTRUCTION DIAGRAM
I
Transaxlemount
‘i::
+g
/v 1b-8
8-,
Enaine mount
A
CenterkemberC&s member

Cavity
CavityCavityolAO284Turbo.
4WD 0lW630OlRO764

9-22ENGINE- Mounts
Principalaxi? of inertia
The
::I: indicates mount positions.01 RO77OlAbsorption action during minute vibrations
ICavity
CavityOlRcl767l
Absorption during large vibrations or “rolling”
Cavity
CavityPRINCIPAL AXIS INERTIA SUPPORT SYSTEM
The vibrations generated from the engine and drive train
consist of such eiements as vertical vibrations caused by the
engine’s combustion processes, as well as
rollings caused by
the torque reaction force of the tyres and the crankshaft
rotation etc.
In order to effectively suppress these vibrations, the principal
axis of inertia support system, by which the components that
contact the principal axis of inertia are mounted, is employed.
INSULATORS
Absorption of Minute Vibrations
The minute vibrations that are generated during idling and
during driving are absorbed because the spring constant is low
as a result of the fact that insulator A only causes vibration of
the space within the cavity.
Absorption of Larger Vibrations
The larger vibrations that are generated during starting from a
_stop and during acceleration are absorbed because insulator A
and insulator
B contact, and the spring constant becomes high.

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

FUEL SYSTEM- duel Supply and Fuel Pressure Control
FUEL SUPPLY AND FUEL PRESSURE CONTROL
GENERAL DESCRIPTION
Fuel tankFuel gauge unitIOJAOt26
Fuel presbreregulator
Fuel gauge
Fuel tankunit - -IEngine control\I
unit
Fuel pumpcheck terminal\
TLo-way valve
Fuel p&sure
regulatorOUO227
RIUXAB