fuel pump MITSUBISHI ECLIPSE 1990 User Guide

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.

--
,
14-24FUEL 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.

I
j:Battery
14-26FUEL SYSTEM - Sensors
INHIBITOR SWITCH The inhibitor switch’s ON (when “N” or
“P”) or OFF (when
other than “N” or
“P”) signals are input to the engine control
unit. The engine control unit, based on these signals, then
determines whether the transaxle is in neutral or is in a drive
range, and then activates the idle-speed control servo so as tc
regulate the idling rpm.
S terminal
---
@
Starter
(Armature)
YT
6FU114!
CONTROL RELAY (Fuel pump drive signal)
This relay senses that power is supplied to the pump.
-If power failed to be supplied to the fuel pump during
er,, .ecranking or during driving, the engine control unit judges that a
fault has occurred and stores corresponding diagnosis code
(No. 42) in memory and at the
sa’me time, causes the engine
alarm lamp (Mulfunction indicator lamp) to come on.IGNITION
COIL (Engine ignition signal)From ignition switchEngine control unit
Ignition
-Elsignal sens-
ing circuit
3)
ffuo573
-
JThis coil senses generating state of the ignition
signal.If abnormal condition occurs during engine
opera-tion such as the ignition signal not being generatedat ignition timing, The engine control unit stores
corresponding diagnosis code (No. 44) in
memoWand at the same time. causes the engine alarm
lamp(Mulfunction indicator lamp) to come on.

FUEL SYSTEM- Engine Control Unit14-29
SFUllSOTerminal
ConnectionTerminalConnectionNo.
No.
1Self-diagnosis output53EGR control solenoid valve (California only)
2Diagnosis/data transfer select terminal54Power transrstor for No. 1 and No. 4 cylinder
‘3Turbo meter
55Power transistor for No. 2 and No. 3 cylinder
4Oxygen sensor56Control relay (Fuel pump control)
5Power steering oil pressure switchl 57Fuel-pressure control valve
6Idle position switch58Coil “Al ” for idle speed control servo
7Air conditioner switch59Coil “A2” for idle speed control servo
8Intake air temperature sensor60No. 3 injector
l 9Detonation sensor61No. 4 injector
10Air flow sensor62Purge control solenoid valve11
-63Control relay
12Ignition timing adjustment connector64Engine warning irght (Malfunction indicator light)
13Control relay (Fuel pump drive signal)65Air conditioner relay
l 14Air flow sensor active filter reset66Control relay
15EGR temperature sensor (California only)67Coil “Bl ” for idle speed control servo
16Barometric pressure sensor68Coil “B2” for idle speed control servo
17Sensors ground101Ground
18Vehicle speed sensor102Power supply
19Throttle position sensor103Power supply for backup
20Coolant temperature sensor
104Inhibitor switch
21Crank angle sensor‘105
Waste gate solenoid valve
22Top dead center sensor106Ground
23Power supply for sensors (5 volts)107Power supply
24Sensors ground108“ST” terminal for ignition switch
51No. 1 injector109Ignition pulse detect
52No. 2 injector170“IG ” terminal for ignition switch
NOTETerminals indicated by the l symbol are applicable only to turbo models.

14-30SELF-DIAGNOSISFUEL SYSTEM- Engine Control Unit
There are 16 diagnosis items, as listed below; the
diagnosis results are stored in computer memory.The diagnosis memory is maintained by backup
The stored results can be ready by connecting apower from the battery (not by way of the ignition
circuit tester or voltmeter to the diagnosis
connec-switch) so that it will not be lost even if the ignition
switch is turned OFF.
tor.
DiagnosisOutput pattern
codeEl
None
lP
@ 11l-l
@ 12n@ 13
@ 14
@ 21Ul n
Diagnosis items
Faulty computer in the engine control unitMalfunction of the air/fuel ratio control system
Open or short circuit in the oxygen sensor circuit
Open or short circuit in the air flow sensor circuit
Open or short circuit in the intake air temperature sensor
circuit
Open or short circuit in the throttle position sensor circuit
Open or short circuit in the engine coolant temperature sensor
circuit
022u1 nn
No voltage change of the crank angle sensor signal
,
@
23
u u-inn
No voltage change of the TDC sensor signal
24uu-uvinnnnNo voltage change of the vehicle speed sensor signal
Q25uuuuuunnnnnOpen or short circuit in the barometric pressure sensor
2 31I-~-~---~ nOpen circuit in the detonation sensor circuit
@ 41uuul nOpen circuit in the injection circuit
042UUuLJul
Malfunction of the control relayOpen or short circuit in the fuel pump drive circuit
z 43UUULnlulMalfunction of the
EGR system
Open or short circuit in the EGR temperature sensor circuit
%4u u u uvinnOpen circuit in either of ignition coil circuit
0nNormal (with none of above faults)
. IA-r-NUltl 1: l 2: for California@ denotes items indicated by an illuminated engine warning light

FUEL SYSTEM -Idle Speed Control14-51
_ 0 (32)80 (175)Coolant temperature “C (“F)6FUO2653
ATarget position during operation
of the power steering systemIDLE CONTROL SERVO POSITION CONTROL WHEN THE
ENGINE IS IDLING
(1) Basic position
The basic position is preset as a map value Optimized
according to the engine coolant temperature. The idle
speed control servo is activated to conform to this position,
thereby maintaining the optimum idle speed.
This basic position of the idle control servo
diiectlycorresponds to the basic idle speed described earlier.
1II
0(32)
80(176)Coolant temperature
“C VW6FUO291Servo position
during operation of
the air conditioner
0(32)
80(176)Coolant temperature “C (“F)6FUO757
1L)760 (30)Barometric pressure mmHg
(in.Hg)BFUlOlC(2) Servo position during shift to “D” range
For models equipped with the automatic
transaxle.when
the position of the shift lever is anywhere other than the
“P” or “N” range, the servo position is increased in
proportion to the load of the torque-converter.
(3) Idle control servo position during operation of the power
steering system
When the power steering oil pressure switch is turned on
because the steering wheel is being turned while
thevehicle is stationary, the servo position is changed to
correspond to the increased power steering pump load.
(4) Servo position while the air conditioner is being operated
When the air conditioner switch is turned on, the servo
position is changed to correspond to the increased air
conditioner load.
(5) High altitude compensation
A correction is performed by increasing the opening of the
idle speed control servo to allow increasing bypass air flow
in order to compensate for the loss of intake air volume
(asmeasured by weight) caused by a reduction in intake air
density due to a drop in barometric pressure at increased
altitude.
(6) “Training” function
A “training” function that enters a value based upon the
engine rpm and the target rpm into the memon/,
andcorrects the servo position according to this value, is
provided in order to obtain an even higher degree of
precision of position control.

FUEL SYSTEM- Power Supply Control
Battery
L11The engine control unit controls the power
suv ’tcthe sensors, engine control unit and
actuate,A;the control relay.
-P
.
-p.Ignition switch
Inn yr
To air flow sensor,crank angle sensor,idle speed controlsetvo. injectors
Control relay
Relay controlFuel pump
controlIgnitionswitch signal
Enginecontrol
unit
I6FUOl’
Power Supply ControlWhen the ignition switch on signal is input, the
engine control unit energizes the control relay coil
L3to turn on the
S2 switch, thus supplying power to the
injectors, air flow sensor, idle speed control servo,
Fuel Pump ControlWhen cranking the’engine (ignition switch at the ST
position), the engine control unit energizes the
Lcoil to turn on the
S switch, thus activating the fuel
pump.While operating the engine (ignition switch at the
IGposition), the crank angle sensor signal is input to
the engine control unit, which energizes the
L,
etc.Approximately seven seconds after input of
theignition switch off signal, the unit turns off the
Sswitch.
control relay coil to keep the
SI switch on, thus
continuing to activate the fuel pump.
When the crank angle sensor signal fails to be
inputfor 0.6 second or longer due to engine stalling,
.,the engine control unit immediately turns
thz. 5switch off to stop the fuel pump as a safet)
precaution.

AUTOMATIC TRANSAXLE - Torque Converter
TORQUE CONVERTER
Lock
ring
I
Damper
F
clutch-
B-.Turbine
.AA
/:ront cover
h,Impeller
AStartorWhen damper clutch is
I\When damper
aInput shaftactivated
clutch isactivated
175202The torque-converter is composed of the impeller
(rear cover), turbine,
stator, damper clutch, one-way
clutch, front cover, etc.Furthermore. the torque-converter cannot be dis-
assembled because the outer circumference of the
shell
(front cover and rear cover) is sealed by
welding.
Because the torque-converter is coupled to the
engine’s crankshaft (via the drive plate). the shell
(front cover and impeller) always turns in the same
way when the engine is running.
As a result, the oil pump is also caused to rotate (by
the hub welded to the center part of the rear of the
shell) at the same speed as the engine.
The boss at the front part of the shell is inserted in
the hole at the rear part of the crankshaft. thus
providing support of the torque-converter.
A facing like that attached to the transaxle’s clutch
disc is attached to the damper clutch, and the
damper clutch and the turbine are connected by the
tabs (of the lock ring on the outer circumference of
the turbine shell) that fit into the groove on the outer
circumference of the damper clutch.
The torque-converter actuation hydraulic pressure,at the damper clutch activation area, passes be-
tween the torque-converter’s hub and the reaction
shaft, and enters the torque-converter.
When this happens, the hydraulic pressure acts
upon the A part (between the damper clutch and the
turbine), with the result that the damper clutch is
pressed against the front cover, and the damper
clutch, with a slight slip (as described later) becom-
es connected.
In this manner, the amount of slippage of the
torque-convener is reduced, without a damper
spring, to far below at even the low-speed level,
thus making a practical improvement of fuel con-
sumption.
At the damper clutch non-activation area, because
the torque-converter actuation hydraulic pressure
passes through the input shaft oil passage
-1enters the torque-converter from the
B part &-tween the damper clutch and the front cover). the
damper clutch moves away from the front
cover,thus releasing the damper clutch.
In this condition, operation is as an ordinary torque-
converter.