fuel pressure MITSUBISHI GALANT 1989 Service Service Manual
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1989, Model line: GALANT, Model: MITSUBISHI GALANT 1989Pages: 1273, PDF Size: 37.62 MB
Page 223 of 1273
FUEL SYSTEM
@ Harness sideconnector
6FU1265
n
8171615141312 11 9 1171615141312~1~1
0
I
Measure the power supply voltage of
the vehicle speed sensor.
. Connector: Disconnected
. Ignition switch: ON
6&loIw I
Voltage (V)
I4.5-4.9--I
Repair theharness.
II
I
Check for continuity of the ground
circuit.
Connector: Disconnected
Repair the
harness.
@WGround)
SENSOR INSPECTION
Refer to GROUP 54-Meters and Gauges.
POWER STEERING PRESSURE SWITCH MI3Yclha
------LI~lI I’ 6FUO65f
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Engine
Power steering 1@
blHarness sideconnector
Enoine control module connector
Page 224 of 1273
13-82 FUEL SYSTEM
OPERATION
l The power-steering pressure switch functions
to convert data as to whether there is or is not apower steering load to LOW-or HIGH-level vol-
tage, and the resulting signals are input to the engine control module. The engine control mod-
ule, based upon those signals, regulates the
idle-speed control motor. l The battery voltage within the engine control
module is applied, by way of the resistance, to
the power-steering pressure switch. When
steering maneuvers are made, the pressure of
the power-steering oil increases, thus switching
ON the power-steering pressure switch, with
the result that the current is grounded. As a re-
sult, the power-steering pressure switch vol-
tage changes from HIGH level to LOW level.
INSPECTION I) Using Scan tool
Function
Item No.
Data reading 27
Data displayInspection conditions Steering wheelNormal indication
Switch status Engine: IdlingSteering wheel idle stateOFF
During steering wheelONoperation
(2) Checking Oil Pressure
Steering wheel
Straight forward
Turned
Oil pump delivery pressure (ref. value)
less than 1,470- 1,961 kPa (213-284 psi)
more than
1,470- 1,961 kPa (213-284 psi)
HARNESS INSPECTION
I-E-I
Harness side connector 6 0
@=- -0
Q
4 1
Measure the power supply voltage.
. Connector: Disconnected. Ignition switch: ON
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13-88 FUEL SYSTEM
TROUBLESHOOTING HINTS
Hint I’
The exhaust gas purification performance will
Examples:
(1) Malfunction of an injector.
worsen if there is a malfunction of the oxygen sensor. Hint 2:
If the oxygen sensor output voltage deviates from
the standard value even though the results of the
checking of the oxygen sensor are normal, the
cause is probably a malfunction of a component related to mixture control. (2) Air leakage into the intake manifold from a
leaking gasket.
(3) Malfunction of the volume air flow sensor, the intake air temperature sensor, the barometric-
pressure sensor, or the engine coolant tempera-
ture sensor.
Data reading
INSPECTION
Using Scan tool
HARNESS INSPECTION
Data display
Sensor de-
tection vol-
tage Inspection conditions
Engine conditionStandard value
Engine: warm up When sudden decel-
250
mV or lower
(Make the mixture lean eration from 4,000 rpm
by engine speed reduc-
tion, and rich by racing) When engine is sud-
500- 1,000 mV
denly raced
Engine: warm up750 rpm (Idling)
(using the oxygen sen-
sor sianal.
check the air/
400
mV or lower
I I
(changes)
fuel mixture ratio, and600-l ,000 mValso check the condition 2,000 rpm
of control by the engine
control module)
I CALIF@I Hal
FEDHarness
ness
side
connector
Engine control
module harness
side connector
Check for an open-circuit, or a short-circuit to ground between the engine
control module and the oxwen sen-f7 _-
~~SOT.‘-. r$;rdn sensor connector: Drscon-
. Engine control module connector:Disconnected CALIF
Harness side
Check for continuity of the ground
.“‘..“...;;”
Repair theharness.
KEEI-Ground)
1
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Page 232 of 1273
13-90 FUEL SYSTEM
INJECTORS
Fuel
Connector
Solenoid coil
Plunger
Needle valve -----I
InjectionFilter6FUO514
M13rrAA
Multiport
fuel injection relay
No.1 &j No.2& No.3& No,4+
tI
lFUO642
Engine control module connector
CJ=JW=U-I
0 1 LO636
OPERATION
l The
injectorsare electromagnetic-valve-
equipped injection nozzles that function to inject
fuel based upon injection signals from the
engine control module.
lBecause the surface area of the injection ports is
fixed and because the pressure of the fuel
relative to the pressure within the manifold is
also regulated to a fixed pressure, the amount of
fuel injection by injectors is determined by the
TROUBLESHOOTING HINTS
Hint 1:
If there is a problem with starting while the engine is
warm, perform the combustion test and check for leakage of the injectors.
Hint
2,
If the engine can’t be started, and the injectors are
not activated during cranking, the cause is probably
a malfunction such as described below, not with the
injectors.
(I) Malfunction of the circuit for supply of power to the engine control module, or of the ground cir-
cuit.
(2) Malfunction of the multiport fuel injection relay.
(3) Malfunction of the crankshaft position sensor and/or the camshaft position sensor.
Hint
3.
If there is a cylinder for which the idling condition
does not change when, during idling, the fuel length of time that the needle valve is open, or,
in other words, by the length of time of current
~-
flow to the solenoid coil.
lBattery power supply is supplied, by way of the
multiport fuel injection relay, to the injectors.
When the engine control module switches ON
the power transistor within the unit and current
flows to the solenoid coil, the injectors open and
fuel is injected.
injection of the injectors is cut off in sequence,
check that cylinder as described below.
(1) Check the injector and harness.
(2) Check the spark plugs and the high-tension
cable.
(3) Check the compression pressure. Hint 4:
If the injector activation time deviates from the
standard value even though the results of the
checking of the injector’s harness and of the injector itself are normal, the cause may be pressumed to
be one of the following,
(1) Incomplete combustion within the cylinder. (Malfunction of the spark plugs, the ignition coil,
the compression pressure, etc.)
(2) Incomplete close contact of the EGR valve seat.
(3) Increased engine resistance.
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Page 243 of 1273
FUEL SYSTEM
EGR SOLENOID
L
Multiport fuel injection
EGR solenoid Component@I side connector
_ ”
Enginecontrol
module
LOlW557
01 LO838
OPERATION
l The EGR solenoid is a duty-control type of sole-
noid valve; it performs its control function by
leaking the EGR valve-activation vacuum to the
throttle body A port.
TROUBLESHOOTING HINTS
If the diagnostic trouble code for EGR system
malfunction is output even though the results of
checking the EGR solenoid harness and the
INSPECTION
l Battery power supply is supplied, by way of the
multiport fuel injection, to the EGR solenoid.
When the engine control module switches OFF
the power transistor within the unit, current stops flowing to the coil, and the EGR valve-ac-
tivation negative pressure leaks.
component itself are normal, check the EGR valve,
the vacuum hose piping, and the EGR passage for
clogging.
Using Scan tool
Function Item
No.
Actuator test
10
Description Inspection conditionsNormal condition
$i;;,oi$;;alve switched from Ignition
switch: ON Operating sound is
heard when driven.
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Page 244 of 1273
13-102 FUEL SYSTEM
- On-Vehicule Inspection of MFI Components
HARNESS INSPECTION
Harness sideconnector
L
Harness side
connector
Engine
1
control module
Check for an open-circuit, or a short-
circuit to ground between the EGR
solenoid and the engine control mod-
harnessule.side. EGR solenoid connector: Discon-connectornected+ Engine control module connec- tor: Disconnected Repair the
-+ harness.
Kzix2l-a)
-I
Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
-
ACTUATOR INSPECTION
Refer to GROUP 17-Exhaust Gas Recirculatin (EGR) System
.
FUEL PRESSURE
RELEASE OF RESIDUAL PRESSURE FROM HIGH PRESS-
URE FUEL HOSE
Make the following operations to release the pressure remain-
ing in fuel pipe line so that fuel will not flow out. @ Disconnect the fuel pump harness connector at the fuel
tank rear side.
@ Start the engine and after it stops by itself, turn the ignitionswitch to OFF.
@ Disconnect the battery (-) terminal.
@I Connect the fuel pump harness connector.
FUEL PUMP OPERATION CHECK
(1) Connect the (+)
battery terminal to the fuel pump drive
terminal and the
(-) terminal to the chassis. Confirm that
the fuel pump operates at this time.
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Page 245 of 1273
FUEL SYSTEM
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---
I g$qfq, tcJ-s6FUO633
(2) Lift up the chassis, and disconnect the connector from the
fuel pump which is mounted on the rear area of the fuel
tank.
(3) Check the terminals, wiring, etc., for damage.
(4) Using an ohmmeter, check the motor continuity.
FUEL PRESSURE TEST
(1) Reduce the internal pressure of the fuel pipes and hoses.
(Refer to P.13-1 OZ.)
(2) Disconnect the fuel high pressure hose at the fuel rail
side.
Caution
Cover the hose connection with shop towel to prevent
splash of fuel that
could be caused by some residual
pressure in the fuel pipe line.
(3) Place the
MD998742-01 adapter on the end of the
fuel rail, then attach the fuel high pressure hose to the
adapter using the bolts supplied with the
MIT2 10196 fuel
pressure test assembly.
(4) Attach one end of the fuel hose supplied with the
MIT21 0196 to the quick-disconnect fitting on the
MD998742-01 adapter. Attach the other end of the hose
to the fuel pressure gauge.
(5) Connect the
(-) battery terminal.
(6) Connect a jumper wire to the fuel pump check terminal and to the positive
(+) terminal of the battery to activate the
fuel pump. With fuel pressure applied, check to be sure
that there is no fuel leakage from the fuel pressure gauge
and the special tool connection part.
(7) Disconnect the jumper wire (from the fuel pump check
terminal) to stop the fuel pump.
(8) Start the engine and let it idle.
(9) Measure the fuel pressure during idling.
Standard value: Approx. 270 kPa (38 psi) at curb idle
Page 246 of 1273
13-I 04 FUEL SYSTEM
the vacuum hose from the fuel pressure
regulator, and then measure the fuel pressure while using a
finger to plug the end of the hose.
Standard value:
330-370 kPa (47-53 psi) at curb idle
speed
(11)Check to be sure that the fuel pressure during idling does
not decrease even after the engine is raced a few times.
(12)&e a finger to gently press the fuel return hose while
repeatedly racing the engine, and check to be sure that
there is fuel pressure in the return hose also.
NOTE
There will be no fuel pressure in the return hose if there is
insufficient fuel flow.
(13)lf the fuel pressure measured in steps (9) to (12) deviates
from the standard value range, check for the probable
cause by referring to the table below, and then make the
appropriate repair.
Condition Probable causeRemedy
. Fuel pressure IS too low. Fuel filter is clogged.Replace the fuel filter.
. Fuel pressure drops during racing.. No fuel pressure In fuel return hose. Malfunction of the valve seat with-Replace the fuel pressure regula-in the fuel pressure regulator, ortor.
fuel leakage to return side caused by spring deterioration.
Fuel pump low discharge pressure.Replace the fuel pump.
Fuel pressure is too
highThe valve within the fuel pressure Replace the fuel pressure regula-regulator is sticking.
tor.
Clogging of the fuel return hose Clean or replace the hose and/or
and/or the pipe.pipe.
No change of the fuel pressure when Damaged vacuum hose or nippleReplace the vacuum hose, or clean
vacuum hose IS connected and when not clogging.the nipple.connected.
(14)Stop the engine and check for a change of the value
indicated by the fuel pressure gauge. The condition is
normal if there is no decrease of the indicated value within
two minutes. If there is a decrease of the indicated value, monitor the
speed of the decrease, and, referring to the table below.
determine the cause of the problem and make the
appropriate repair.
Condition Probable cause
After the engine is stopped, the fuel Injector leakage
pressure drops graudally.
Remedy
Replace the injector.
Leakage at the fuel pressure reg-
Replace the fuel pressure regula-
ulator valve seat tor.
There IS a sudden sharp drop of the fuel The check valve
(within the fuel Replace the fuel pump.
pressure immediately after the engine is pump) is not closed.
stopped.
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Page 247 of 1273
FUEL SYSTEM
fine probe7FU1264 1
(15) Reduce the internal pressure of the fuel pipes and hoses.
(Refer to
P.13-102.)
(16) Disconnect the fuel pressure gauge and the special toolsfrom the fuel rail.
Caution
Because there will be some residual pressure in the fuel
pipe line, use a shop towel to cover so that fuel doesn’t
splatter.
(17)Replace the O-ring at the end of the fuel high-pressure
hose with a new one. (18)After
connecting the fuel high-pressure hose to the fuel
rail, tighten the installation bolt.
(19)Check to be sure that there is no fuel leakage.
@ Apply battery voltage to the terminal for activation of the fuel pump so as to activate the fuel pump.
@ With fuel pressure applied, check for leakage of the fuel
line.
INSPECTION OF ENGINE CONTROL MODULE
TERMINAL VOLTAGEMl 3ZALBa
(1) Connect the extremely fine probe (paper clip, etc.) to the probe of the voltmeter.
(2) At each terminal of the engine control module connector,
insert the extremely fine probe from the wire side, and
measure the voltage referring to the check chart.
NOTE
1. In the state in which the connector of the engine
control module is connected, measure the voltage.
2. Measure the voltage across each terminal to the
terminal No. 106.
(ground terminal).
3. You may find it convenient to pull out the engine control module to make it easier to reach the connector
terminals.
4.Inspection need not be executed in the chart’s sequence.
Caution
Short-circuiting the positive
(+) probe between a con-
nector terminal and ground could damage the vehicle
wiring, the sensor, the engine control module, or all
there. Use care to prevent this!
(3) If voltmeter shows any deviation from standard value, check the corresponding sensor, actuator and related
electrical wiring, then repair or replace.
(4) After repair or replacement, recheck with the voltmeter to confirm that the repair has corrected the problem.
Page 248 of 1273
13-106
FUEL SYSTEM
TERMINAL VOLTAGE CHECK CHART
Terminal arrangement of engine control module connector NflTF
01 LO838
. .- -B+: Battery positive voltage
Terminal
No.Check condition (Engine state)StandardvalueRemarksCheck item
103
Backup power supply lgnitron
switch: OFF
102Power supply ignition switch: ONB+
107
109
Fuel pump dnve signal
Engine: Cranking 8V or higher
Engine: Idling
B+I
Ignition switch: ON
Engine:
ldlrng
Ignition switch: ON
Engine: idling
Engine speed: 2,000 rpm
B+I
o-3v
4.5- 5.5v
2.2- 3.2V
56
23
10
Multiport fuel
injection relay
(Fuel pump)
Sensor
rmpressecvoltage
Volume air flow
sensor
Air intake
temperature sensor Ignition
Air intake temperature of
0°C (32°F)switch:ONAir Intake temperature of 20°C (68°F); ji/
Air Intake temperature of 40°C (104°F)1.5-2.1V
Air intake temperature of 80°C (176’F)0.4- 1 .OV
Barometric
pressure sensor
Ignition
Altitude of 0 m (0 ft.)3.7-4.3vswitch:ON Altitude
of 1,200 m (3,937 ft.)3.2-3.av
Engrne coolant lgnitron
Coolant temperature of 0°C (32°F)3.2-3.Wtemperature switch: -sensorONCoolant temperature of 20°C (68°F)2.3-2.9v
1 Coolant temperature of 40°C
(104°F) 1 1.3- 1.9V(
) Coolant temperature of 80°C
(176’F)
1 0.3-0.9V
Throttle posrtionsensor Ignition swatch: It
Set the throttle valve to the
is kept ON for 15
seconds or more
Closed throttle position switchII
I
I
-
Ignition Set the throttle valve to the idlingo-1vswitch:position.3NSlightly open the throttle valve. 4V
or higher
3
16
!O
9
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