diagram MITSUBISHI ECLIPSE 1990 User Guide

14-16FUEL SYSTEM - Sensors
TransmitterMEASUREMENT OF INTAKE AIR FLOW
(1) When there is no air’ flow
No vortices are generated in the absence of air flow.
Therefore, the ultrasonic waves transmitted from the
transmitter take a fixed time to reach the receiver. This
time is called the “reference time”. This time shall be
referred to as
“T”.
Recetver6FUo42!
6FUO426
6f UO42;
TIT1Tl
~tee;ence
9%
T22
Pulses generated by modulator
(2) When a clockwise vortex passes under transmitter
When a vortex passing between the transmitter and
receiver revolves clockwise, the direction of ultrasonic
wave transmission is the same as that of the air movement
of the leading half of the vortex, so that the time elapsed for
the ultrasonic waves to reach the receiver is shorter than
the reference time.
This time shall be referred to as
“T, “.
In the trailing half of the vortex, the directions of the wave
transmission and the vortex air movement are opposite to
each other, thus the elapsed time required by the ultrasonic
waves to reach the receiver becomes longer.
(3) When a counterclockwise vortex passes under the trans-
mitter
When the vortex passing between the transmitter
and-.receiver revolves counterclockwise, the direction of ultr:
sonic wave transmission and that of the air movement
OTthe vortex are opposite to each other for its leading half,
thus the time taken for the ultrasonic waves to reach the
receiver is longer than the reference time. This time shall
be referred to as
“Tz”.In the trailing half of the vortex, the directions of the two
are the same so that the time taken for the ultrasonic
waves to reach the receiver becomes shorter than the
reference time.
(4) When clockwise and counterclockwise vortices are passing
in an alternate fashion
When clockwise and counterclockwise vortices are passing
alternately between the transmitter and the receiver, the
time taken for ultrasonic waves to reach the receiver
changes as illustrated in the upper diagram at the left.
(5) Modulator generated signal
Each time the “T2” point is passed and transmission time
converges on the reference time “T”, the modular gener-
ates one pulse.
-

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
*
<c
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

._ ..-
14-58
.-FUEL SYSTEM
- Accelerator Components
-7
ACCELERATOR COMPONENTSRlUUAAThe accelerator is the cable type, and the pedal is
the suspended type.
A nylon bushing is installed on the end of the
accelerator cable, preventing contact noise
be-tween the cable and accelerator arm from beinggenerated.
In addition, the accelerator pedal switch, which is
used as a control sensor on models with the4-speed NT, is equipped at the pedal support
member.
CONSTRUCTION DIAGRAM
Accelerator cable
Accelerator pedal
switch
<MBITNylon
bushing
\Accelerator
cableAccelerator
ahmember
Accelerator
Accelerator
pedal

FUEL SYSTEM -Auto-cruise Control System14-59AUTO-CRUISE CONTROL SYSTEMRIIPA&A
using the auto-cruise control system, the vehicle
oar-rbe maintained at a constant driving speed
[between 40 km/h (25 mph) or higher and 145 km
(90 mph) or lower], as selected by the driver,
without using the accelerator pedal.The actuator is the DC motor-driven type for a high
degree of adherence to the set speed. A flexiblesupport system is used for installation of the
actuator in order to prevent the transaxle of body
vibrations to the actuator.
CONSTRUCTION DIAGRAM
control switchOJAO2SS
Accelerator
Actuator
ab’ea\ A
Inhibitor switch <mh/&
Vehicle speed sensor
(reed switch)
Accelerator cab1e.A/IClutch switch <M/T>
/Accelerator pedal switch <A/T>IStop light switch

-.
14-60FUEL SYSTEM - Auto-cruise Control System
SYSTEM BLOCK DIAGRAM
---
f?,: 0,
,’
vi
switch cpJT>
Auto-cruise control switch. MAIN switchl SET (COAST) switchl RESUME (ACCEL) switc
I
Intermedi-ate linkActuator
mechanismCOMPONENT PARTS AND FUNCTION OUTLINE
Component part
Vehicle speed sensor
6\uto-cruise control unit
Function
Converts vehicle speed to pulse,
Receives signals from sensor and control switches; microcomputercontrols all auto-cruise control functions
ActuatorRegulates the throttle valve to the set opening by signals from the
auto-cruise control unit
Control switchMAIN switch
Switch for auto-cruise control power supply
SET
(COAST) switchControls auto-cruise control functions by SET (COAST) and
1 RESUME (ACCELIRESUME (ACCEL) switch
Cancel switch
Stop light switchClutch switch
<M/T>Outputs the auto-cruise control cancel signals
Inhibitor switch CA/T>
Accelerator switch
<A/T>During constant speed driving, the accelerator pedal is inactive and
the accelerator switch is turned ON.
Therefore, OFF signal is output from the auto-cruise control unitto the ELC
4A/T control unit during constant speed driving only.
4-I-Ed automatic transaxle control unitControls overdrive ON and OFF based on overdrive ON andOFF signals from the auto-cruise control unit for the auto-cruise
controlAuto-cruise indicator lightThis indicator light illuminates to indicate that the vehicle is
traveling in the auto-cruise mode.
Diagnosis connectorBY connecting a voltmeter control unit diagnosis and input-check
codes can be read out (for details, refer to P. 14-69).

F
FUEL SYSTEM -Auto-cruise Control System'l4-61
AUTOCRUISE CONTROL UNIT
Je auto-cruise control unit incorporates a micro-computer which provides the set coast, resume,
acceleration, cancel, low-speed limitation,
high-speed limitation, overdrive OFF control, and
auto-
matic cancellation functions. The microcomputer
inputs signals from the vehicle speed sensor and
the switches, and outputs Control signals to the
actuator’s DC motor, the electromagnetic clutch,and the automatic
.transaxle (4 A/T) control unit in
accordance with the programming (software) of themicrocomputer.
CONTROL LOGIC BLOCK DIAGRAM
--
Auto-cruise control UnitIgnitionswitcha.-.
I
Input interface circuit
piz7q.f~~
I
L
Micro-
computer
jutput interface circuitIr--lI----
--7I IActuatorI
Electromagnetic
clutch coil
OD-OFF out-
put circuit
NC: Normally closed

FUEL SYSTEM -Auto-cruise Control System14-65OVERDRIVE-CANCEL FUNCTION
<A/T>
%/hen, during fixed-speed driving, the actual vehicle
speed decreases to (or below) a speed which is a
certain fixed value below the memorized vehicle
speed, the overdrive is canceled temporarily for a
specified period of time and then the memorized
vehicle speed is restored within a short period of
time.
Overdrive is canceled under any of the following
conditions:
8 When the RESUME switch is being operated.
l When, during fixed-speed driving, the actual
vehicle speed decreases from the preset speed
by 1.25 km/h (0.8 mph) or more.
The arrow in the circuit diagram indicates the flow of
current with the OD switch in the ON position
(overdrive).In the Overdrive Mode
The control unit microcomputer Outputs an OD-ON
signal (HIGH) constantly, keeping transistor
Tr,turned ON. At this time, transistor
Tr, is also ON,
causing ON signal
IA to be output to the transaxle
control unit and maintaining the overdrive mode.
The Overdrive is Canceled
When the actual vehicle speed becomes less than
the set speed, the OD-ON signal (HIGH) is no longeroutput from the microcomputer and transistor
Tr, is
turned OFF. This causes transistor
Tr, to be turned
OFF and current
II: flowing by way of the OD switch
of the selector lever is cut off at transistor
Trl. As a
result, at that point the vehicle speed is controlled
by the
3-speed automatic transaxle.
Auto-cruise control unit

Y 5-FUEL SYSTEM
- Auto-cruise Control System14-71ACTUATOR CONSTRUCTION
The actuator unit consists of a DC motor, a worm
gear, a worm wheel, a planetary pinion gear, a
magnetic clutch, and two limit switches.
The magnetic clutch consists of a magnetic coil
mounted to the actuator case and a clutch plate
connected to the ring gear of the planetary wheel
gear by a spring.The magnetic clutch is energized and deenergized
by the control signal supplied by the control unit.
The clutch transmits the rotation of the DC motor to
the selector drive shaft, and allows the selector
drive shaft to rotate freely with the ring gear
regardless of whether the DC motor is being
energized or not.
Internal construction
Clutch plate
Maanetic clutch coilI ^. ,Planetan/ pinionCircuit diagram
MAIN switch
%tn m.=ir
Auto-cruise control unit
7S&&or drive shaft
Worm gear03R0077
Cross-section of actuator installation
Actuator bracket

47- --.-~.._ ____- -- -..
1”
--- . ._. . ^. I-, ,.>.-,-- ._,..“ _ .L,_. . aL.3. . . . z . .ii.li,“i&,.).. . ..-.-. A .I...‘.- % .a _.” Y-T-- - .;; . ..:h:’
16-1
;iiPROPELLER SHAFT
z,-:
CONTENTSRlaA.-.
24g
:CENTER BEARING . .._._.............................................. 4
IGENERAL INFORMATION. . . . . . . . . .. . . . . . . . . .
.. . . . . . . . . . . . . . .i:Constructio nDiagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . .2
Specification s. . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .*.................
3
LOBROOJOINT. . . . . . . . . . . . . . . . . . . . . . . . . . . .

.-_. -
17-8REAR SUSPENSION <4WD> - Geneal information
REAR SUSPENSION <4WD>GENERAL INFORMATION
Rl7BEThe rear suspension is a newly developed double
wishbone independent suspension with a toe-in
correction feature utilizing compliance of thebushing to external force, and provides
excellesteering stability and a good ride.
The special features of this suspension include
l Optimum adjustment of suspensiongeometry
l Optimum adjustment of alignment
change
0 Passive toe-in correction function
l Optimum combination of spring constant,
shock absorber damping force. andbushing characteristics
l Elastic support of the doubleanti-vibration croSsmemberl Improvement of straight-forward
motion stability
0 Improvement of cornering
stability
l Improvement of steerability
l Good balance ofride andsteering stability
( , , :l Low noise and
low vibrationCONSTRUCTION DIAGRAM
absorber
Trailing arm
.
12AC