1990 MITSUBISHI ECLIPSE oil

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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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-_ .---

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.
-

=--Y
jl
1 /
i "
_. ---“._ _ _ ._ ..-..+_LI_y_--- -
9-2ENGINE- General Information
GENERAL INFORMATION
MAJOR
SPEClFlCATiONS
Row- -
Items
Number and arrangement of cylinderCylinder bore x stroke
mm (in.)
Total displacementcc (cu.in.1Compression ratio
Combustion chamber
Valve mechanismNumber of valve
Intake
Exhaust
Valve timing
IntakeOpen/CloseExhaust Open/Close
Lubrication
Oil pump
Fuel system
SuperchargerCooling system
Water pump
Alternator
Starter motor
Ignition system
Exhaust gas recirculation systemCatalytic converter
Crankcase ventilation system
Evaporative emission control system
Non-Turbo engineTurbo engine4 in-line, longitudinal
4 in-line, longitudinal
85 x
88 (3.346 x 3.465)85 x 88 (3.346 x 3.465)1997 (121.9)
1997 (121.7)
9.07.8
Pentroof typePentroof type
Double overhead camshaftDouble overhead camshaft
(DOHC)(DOHC)
88
88
26 “BTDU46”ABDC21”BTDC/Sl”ABDC56BBDUS”ATDC55”BBDUS”ATDC
Pressure feed-full flow filtrationPressure feed-full flow filtration
Gear typeGear type
Electronic control multipoint
fuelElectronic control multipoint fuel
injectioninjection
Turbo typeLiquid cooled-forced circulationLiquid cooled-forced circulation
-Impeller typeImpeller type
AC generator with a built-involtage regulatorAC generator with a built-in
voltage regulator
Planetary gear reduction drivePlanetary gear reduction drivetype
Two-coil type, electronic controlTwo-coil type, electronic control
ignitionignition
Conventional type: For FederalConventional type: For Federal
and Canadaand Canada
Electronical control type:Electronical control type:
For CaliforniaFor CaliforniaMonolithic type,
under-floorMonolithic type, under-floor
installationinstallation
Closed typeClosed type
Charcoal canister typeCharcoal canister type
I

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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s’ y _._----,_ - k - ..-_ _ _
ENGINE- Base Engine9-7I
BASE ENGINE
Valve seat
Squish area
Spark plug hole
Exhaust portintake port
Piston O.D.
6EN0076Camshaft lubricatingValve guide
6ENO246Camshaft lubricating
oil passage
6ENO247
(1) The combustion chamber is of the pentroof(2) The spark plugs are located at the center of the
type. The two intake and two exhaust ports arecombustion chambers.
in a crossflow arrangement. There is a
squish(3) The camshaft bearings are placed at six loca-area provided in the combustion chamber,tions on the intake side, and six on the exhaust
which promotes turbulence, further mixing ofside (see next page illustration). The thrust load
the air-fuel mixture, and more efficient
combus-of each camshaft is transmitted to the No. 1
tion.
bearing.
- ._ _ _ - -,- -- .---

CYLINDER BLOCKENGINE
- Base Engine9-9
Engine oil tocylinder
headCoolant inlet
ASilent
front
Engine oil main gallery
Silent shaft bearing,
rear
\shaft bearing,
A taw
Silenishaft bearing.
rearengine only)
6EN0246
(1) There is an oil jet provided for each cylinder just under the
main gallery of the cylinder block. When the pressure of oil
from the main gallery exceeds 200
kPa (2 kg/cm’, 28 psi),
the oil pushes open the check valve, spurting over the
inside of the piston, thus cooling it. (Turbo engines only)
(2) The water jacket is the Siamese type.

9-10PISTONENGINE- Base Engine
For non-turbo engineldentificatlonForturbo engine
Pin;nterline y FPiston ceyerline
6EN01246EN0125Steel strut6EN0249
Ij(1) The piston is the autothermic type with steel
struts cast into it..(2) The depth of the trough in pistonhead varies for
the non-turbo and turbo engines.
Piston
pinConnecting
rod?\i
~Piston
6EN0250
No. 1 piston ringPISTON RINGS
No.3
For turbo engine
(1) The No. 1 piston ring IS of the barrel type.
(2) The No. 2 piston ring is of the taper type. The surface in
contact with the cylinder wall is coated with hard chrome
plating.-
(3) The oil ring is of the three piece type, consisting of two sLrails and an expander.
.,YM,,fiFNflR7
,
(3) The piston pin is of the semi-floating type, press-fitted to
the connecting rod and rotates freely in the piston.