1990 MITSUBISHI ECLIPSE ABS

o-4GENERAL - Technical Features
BASIC CONSTRUCTION
The 4WD vehicles are equipped with
2.OL DOHC
16-valve turbocharged engine and incorporate new
technologies such as full time 4WD of center
differential type with viscous coupling differential
limiting for excellent running stability and excellent
Steering
l Light weight and compact rack and pinion
type for high steering response
l Tilt steering mechanism to give optimum
driving position
\driving across bad roads, and $-wheel independent
suspension for comfortable riding.
Adopted on
2WD vehicles are 2.OL DOHC 16-valveengine, MacPherson strut type front suspension
and torsion axle
typ.e 3-link rear suspension.
Rear suspension
l Self-aligning double wishbone type suspen-
sion for comfortable ride
(4WD)l Torsion axle type 3 link suspension for
outstanding driving stability
(2WD)l Negative chamber for outstanding steer-
ability during high speed driving
0 Anti-lift geometry for high stability duringbraking
lIntegral torsional bar type axle beam for
optimum roll stiffness (2WD)
\Front propeller shaft (3-piece
4-joint type)
lRobro joint to absorb lengthwise and angular
change and prevent transmission of vibrations.
(4WD)
IFront suspension
The front suspension of McPherson strut type
independent suspension system
l Under steer geometry for outstanding steering
stability
l Negative offset geometry for outstanding
stabil-ity at braking
0 Offset coil springs for comfortable ride
Brakes
l Cross piping dual type proportioning valvethat keeps balanced braking power even at
failure of the hydraulic system.
l Four wheel disc brake system for high
braking power.

FRONT SUSPENSION - General Information2-3
SPECIFICATIONS
<2WD>terns
Suspension system
Camber
Caster
Toe-inmm (in.)
Coil springWire dia. x O.D.
x free lengthmm (in.)Coil spring identification color
Spring constantN/mm (IbsAn.)
Shock absorber
TypeMax. length
mm (in.)Min. length.
mm (in.)
Strokemm (in.)Damping force [at
0.3. m/set. (.984 ft./sec.)l
Expansion
N (Ibs.)Contraction
N (Ibs.)
Non-TurboTurbo
With a manualWith an automatic
With a manualtransaxletransaxletransaxle
McPherson strut with coil spring and compression rod type
5’
z!z 30’
2”24’ 31 30’
0
It 3 (0 * .12)
13.7x173.7x314 13.9x173.9x321.5
(.54 x 6.84 x 12.4)l.55 x 6.85 x 12.7)
Light blue x 1Light blue x 2
24 (134)24 (134)Hydraulic, cylindrical double-acting type
483
(19.02)330 (12.99)
153
(6.02)1,000
(220)300
(66)

FRONT SUSPENSION - General Information
c4WD>Items
Suspension system
CamberCaster
Toe-inmm (in.)
Coil springWire dia. x O.D. x free length
mm (in.)Coil spring identification color
Spring constantN/mm
(Ibs./in.)
Shock absorber
TypeMax. length
mm (in.)Min. length
mm (in.)
Strokemm (in.)Damping force [at 0.3
m/set. (.984 ft./set.)]Expansion
N (Ibs.)Contraction
N (Ibs.)Specifications
McPherson strut with coil spring and compression rod type
10’
+- 30’
2”18’ + 30’
0
zk 3 (0 f .l2)14.0 x 174.0
x 326.5 (.55 x 6.85 x 12.9)
Pink x 1
26 (146)
Hydraulic, cylindrical double-acting type
489 (19.25)
340 (13.39)
149 (5.87)
1,000 (220)
300 (66)

----2-6
FRONT SUSPENSION - Offset Spring
OFFSET SPRINGBecause struts are installed at an angle, the road
surface reaction force
(RI) applied to the tyres tends
to act vertically upon the tyre centre, and that force
tries to bend the strut toward the inside of the
vehicle. When this happens, the force trying to bend
the strut toward the inside of the vetiicle acts upon
the strut bearing component as bending moment
reaction force
FL (because the upper part of the strut
is fixed in place), thus increasing the friction of the
bearing, and, as a result of the bending of the strut,
amplifying the moving resistance of the shock
absorber.Ro2EMA
Then, because the coil spring
is installed so that itscentre is greatly offset (toward the outside of the
vehicle) from the centre of the strut, the counterac-
tive force for the spring tends to become great
toward the outside of the vehicle, thus resulting in
the generation of bending force
FL opposite to the
bending of the strut, and thereby decreasing the
friction applied to the strut bearing. As a result, the
shock absorber’s internal movement friction is
reduced, thereby improving riding comfort as well
as the durability of components.
Spring counteractiveforce
RI : Road surface reaction forceR2: Strut axial-reaction forceR3: Strut bend direction reaction forceR4: Strut bending force (by spring offset)

2-8FRONT SUSPENSION - Front Axle
FRONT AXLEROPKAAAThe drive shaft is of the Bit-field joint
(B.J.)-tripodjoint
(T.J.) type. This type features high power
transmission efficiency and low vibration and noise.The knuckle has the wheel bearing assembled
a@the hub press-fitted. The drive shaft and hub are
spline-coupled.
T.J.: Tripod Joint
B.J.: Birfield Joint
Hub
DRIVE SHAFT
B.J.-T.J. constant velocity joint combination main-
tains speed completely even when flexed, can
withstand heavy loads and shock and offer high
power transmission efficiency. Their special fea-
tures are outlined below.
B.J.T.J.l Axially
slidablel Smaller sliding resistance
0 Large operating angle
l Compact size and decreased space
require-
me&Taking these characteristics into account, B.J. is
adopted on the wheel side of the shaft, as it can
make large deflections when the tire is steered and
T.J. is adopted on the transmission side, as it can
slide
axiallv to absorb the chanae in the distance
between joints caused by
motionWof the suspension.
B.J.T.J.
llA0123

3-4REAR AXLE - Axle Shaft / Drive Shaft
AXLE SHAFT
R03cAAAThe axle shaft is a semi-floating type supported by
ball bearings (outer and inner) in the housing.To prevent mud that may be deposited around the
bearing (outer), a dust cover has been provided.
D.O.J.
Companion flangeIG ?ust cover
Trailing arm
IllA0013
DRIVE SHAFTBirfield type constant velocity ball joints have been
provided for the drive shaft.
On the axle shaft side, the D.O.J. type has been
adopted to absorb the change in distance between
the joints that may be caused by the movement of
the suspension.
On the differential carrier side, the B.J. type has
been adopted which allows considerable flection in
keeping with the movement of the suspension.
Drive shaft and B.J.RO3OAAAOn the axle shaft side, they are coupled with the
axle shaft with the companion flange in between.
On the differential side, they are spline coupled with
the side gears.
On vehicles with a viscous coupling type limited slip
differential, the right and left drive shafts are
different in length. In addition, the B.J. side of the
drive shaft (R.H.) is two-stage serration coupled.
D.O.J. Boot
_vehicles)
D.O.J. Outer race
D&e shaft (R.H.)two-sta e serration(ECLIPS!: Viscous coupling type
limited slip differential equipped
D.O.J. Inner I
llA0338

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

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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