fuel pump MITSUBISHI ECLIPSE 1991 Owner's Manual

FUEL SYSTEM - Service Adjustment Procedures <1.8L Engine>14-47
A
E3x>
/ )Engine speed
(rpm)1 FU446Engine speed (rpm)
>3FU262EGR VALVE CONTROL VACUUM CHECK

Check ConditionEngine coolant temperature: 85-‘95”C (185-205°F)
(1) Disconnect the vacuum hose from the throttle body EGR
vacuum nipple and connect a hand vacuum pump to the
nipple.(2) Start the engine and check to see that, after raising the
engine speed by racing the engine, vacuum raises pro-
portionately with the rise in engine speed.
NOTEIf there is a problem with the change in vacuum, it is
possible that the throttle body port may be clogged and
require cleaning.
PURGE PORT VACUUM CHECKCheck ConditionN14FvBcEngine coolant temperature:
85-95°C (185-205°F)
(1) Disconnect the vacuum hose from the throttle body purge
hose nipple and connect a hand vacuum pump to the
nipple.(2) Start the engine and check to see that, after raising the
engine speed by racing the engine, vacuum remains fairly
constant.NOTE
If there is no vacuum created, it is possible that the throttlebody port may be clogged and require cleaning.

FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>14-51THROTTLE BODY (THROTTLE VALVE AREA)
CLEANINGNl4FtU
(1) Warm up the engine, then stop it.
(2) Remove the air intake hose from the throttle body.
(3) Plug the bypass passage inlet of the throttle body.
CautionDo not allow cleaning solvent to enter the bypass
passage.(4) Spray cleaning solvent into the valve through the throttle
body intake port and leave it for about 5 minutes.
(5) Start the engine, race it several times and idle it for about 1minute. If the idling speed becomes unstable (or if the
engine stalls), slightly open the throttle valve to keep the
engine running.
(6) If the throttle valve deposits are not removed, repeat steps
(4) and (5).
(7) Unplug the bypass passage inlet.
(8) Attach the air intake hose.
(9) Disconnect the battery terminal for 10 seconds or more,
and then reconnect it.
(lO)Adjust the basic idle speed. (Refer to P.14-48.)
RELEASE OF RESIDUAL PRESSURE FROM HIGH
PRESSURE FUEL HOSE
N14FGAFRefer to
P.14-44.FUEL PUMP OPERATION CHECK
N14FDAG(1) Set the ignition switch at OFF.
(2) Check that when the battery voltage is directly applied to
the fuel pump check terminal, the operating sound of the
pump can be heard.
NOTESince the high pressure fuel pump is installed in the fuel
tank, its operating sound cannot be readily heard. Remove
the fuel tank cap and listen to the operating sound through
the filler port.
I(3) Hold the high pressure fuel hose between your fingers and
check that the fuel pressure can be felt.

FUEL SYSTEM - Service Adjustment Procedures <2.0L Enaine>14-53
MD998709
MD998742
I
FU01571-(4) Connect a fuel pressure gauge to the special tool (hose
adapter).Use a suitable O-ring or gasket between the fuel-pressure
gauge and the special tool so as to seal in order to preventfuel leakage at this time.
(5) Install the special tool, which was set in place in step
(4),
between the delivery pipe and the high-pressure fuel hose.(6) Connect the
0 terminal of the battery.
(7) Apply battery voltage to the fuel pump check terminal and
activate the fuel pump; then, with fuel pressure thus
applied, check to be sure that there is no fuel leakage fromthe pressure gauge or the special tool connection part.
(8) Start the engine and run at curb idle speed.
(9) Disconnect the vacuum hose from the pressure regulator
and clog the vacuum hose end. Measure the fuel pressure.Standard value:
Turbo>330-350 kPa (47-50 psi) at curb idle

250-270 kPa (36-38 psi) at curb idle

290-320 kPa (41-46 psi) at curb idle
(10)Measure the fuel pressure when the vacuum hose is
connected to the pressure regulator:
Standard value:
Approx. 270
kPa (38 psi) at curb idle
Approx.
190 kPa (27 psi) at curb idle
Approx. 230
kPa (33 psi) at curb idle

14-54FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>
(11)Race the engine repeatedly in two or three series. Then
check that the fuel pressure does not fall when the engine
is running at idle.
(12)Check to be sure that there is fuel pressure in the return
hose also (by gently pressing the fuel return hose with a
finger while repeatedly racing the engine).
NOTEThere will be no fuel pressure in the return hose when the
volume of fuel flow is not sufficient.
(13)lf the results of the measurements made in steps (9) and
(10) above are not within the standard value, use the table
below to determine the probable cause, and then make the
necessary repair.
Condition
Fuel pressure too lowProbable causeRemedy
a. Clogged fuel filtera. Replace fuel filter.
b. Fuel leaking toward return port due tob. Replace fuel pressure regulator.
improper seating of valve in fuel pressure
regulator
c. Low delivery pressure of fuel pumpc. Replace fuel pump.
Fuel pressure too higha. Stuck valve in fuel pressure
a. Replace fuel pressure regulator.regulator
b. Clogged or bent fuel return hose or pipeb. Repair or replace hose or pipe.
Fuel pressure witha. Clogged or broken vacuum hose or nipplea. Repair or replace vacuum hose or
vacuum hose connected
nipple.
not different from fuel
pressure with vacuumb. Stuck valve in fuel pressure regulator or
b. Replace fuel pressure regulator.
hose not connecteddefective valve seating
(14)Stop the engine and check for change in fuel pressure
gauge indication, which should not drop.
If the gauge indication drops, observe the rate of drop and
determine and remove the causes according to the
following table.
Condition
Fuel pressure drops
slowly after engine is
stopped.Probable cause
Leakage from injectorRemedy
Replace injector.
Fuel pressure drops
im-Check valve in fuel pump does not closeReplace fuel pump.
mediately after engine is
stopped.
(15)Reduce the fuel pressure in the fuel line.
(16)Disconnect the high pressure fuel hose and remove the
fuel-pressure gauge from the delivery pipe.
Caution
Cover the hose connection with shop towel to prevent
splash of fuel that could be caused by residual pressurein the fuel pipe line.
(17)Mount a new O-ring in the groove at the end of the high
pressure fuel hose.

FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>14-55
(18)Connect the high-pressure fuel hose,,to the delivery pipe
and tighten the screws to the specified torque.
(19)Check for fuel leaks.
@I Apply battery voltage to the fuel pump check terminal
to operate the fuel pump.
@ With fuel pressure acting, check the fuel line for leaks.
A
E2li:>
/ )
Engine speed (rpm)lFU4l6EGR VALVE CONTROL VACUUM CHECK
NlQFVBBlCheck Condition
Engine coolant temperature:
85-95°C (185-205°F)
(1) Disconnect the vacuum hose from the throttle body EGR
vacuum nipple and connect a hand vacuum pump to the
nipple.(2) Start the engine and check to see that, after raising the
engine speed by racing the engine, vacuum raises pro-
portionately with the rise in engine speed.
NOTEIf there is a problem with the change in vacuum, it is
possible that the throttle body port may be clogged and
require cleaning.PURGE PORT VACUUM CHECK
Check Condition
N14FVBClEngine coolant temperature:
85-95°C (185-205°F)
(1) Disconnect the vacuum hose from the throttle body purge
hose nipple and connect a hand vacuum pump to the
nipple.
Engine speed (rpm)3FU262(2) Start the engine and check to see that, after raising the
engine speed by racing the engine, vacuum remains fairly
constant.
NOTE
If there is no vacuum created, it is possible that the throttlebody port may be clogged and require cleaning.

14-58FUEL SYSTEM -MPI System Inspection <1.8L Engine>
MALFUNCTION INDICATOR LIGHTNWQAB
Among the self-diagnosis items, a malfunction indicator light
comes on to notify the driver of the emission control items
when an irregularity is detected.
However, when an irregular signal returns to
notmal ‘and the
engine control unit judges that it has returned to normal, the
malfunction indicator light goes out.
Moreover, when the ignition switch is turned off, the light goes
out. Even if the ignition switch is turned on again, the light doesnot come on until the irregularity is detected.
Here, immediately after the ignition switch is turn on, the
malfunction indicator light is lit for 5 seconds to indicate that
the malfunction indicator light operates normally.
Items indicated by the lightening malfunction light
Engine control unit
Oxygen sensor
Air-flow sensor
Intake air temperature sensor
Throttle position sensor
Motor position sensor
Engine coolant temperature sensor
Crank angle sensor
No. 1 cylinder TDC sensor
Barometric pressure sensor
Ignition timing adjustment signal
Injector
Fuel pump
EGR system Caution
The malfunction indicator light lights up when the ignition
timing adjustment terminal is short-circuited
,‘t’o ground.
Consequently, it lights up ,when the ignition timing
adjustment is grounded when adjusting ignition timing,
but in this case there is no abnormality.
MALFUNCTION INDICATOR LIGHT INSPECTlON
When turning on the ignition switch, check that the light comes
on.
NOTElf the light does not come on, check the harness and light for
breakage.SELF-DIAGNOSIS
Nl4PMFaThe engine control unit monitors the input/output signals
(some signals at all times and the others under specified
conditions) of the engine control unit.

FUEL SYSTEM - MPI System Inspection <1.8L Engine>
outputDiagnosis code
referenceDiagnosis itemCheck item (Remedy)
orderOutput signal patternNo.Memory
7Engine coolantRetainedl Harness and connectortemperature sensor
:-rlrLn- 2’
l Engine coolant temper-
ature sensor
12A0107
8Crank angle sensor
:nn 22
Retainedl Harness and connector
(If harness and connector
are normal, replacedistributor assembly.)
12A0107
9No. 1 cylinder top
dead center sensorH
Lnn 23
Retainedl Harness and connector
(If harness and connector
are normal, replacedistributor assembly.)
12A0107
10Vehicle speed sensor24Retainedl Harness and connector
(reed switch)H
Lu 1 nnJln
l Vehicle speed sensor
(reed switch)
12A0107
11Barometric pressure25Retainedl Harness and connector
sensorH
u I nl-uvln
(If harness and connector
are normal, replace
Lbarometric pressure
12A0107sensor assembly.)
12Ignition timing adjust-36-l Harness and connectorment signalH
LUUI nluvuuL
12R0468
13Injector
:m 41
Retainedl Harness and connector0 Injector coil resistance
12A0105
14Fuel pump42Retainedl Harness and connectorH0 Control relay
LUUUI nn
12A0105
15EGR 43Retainedl Harness and connectorl EGR temperature sensor
H
u u u u-inn
l EGRvalvel EGR valve control sole-Lnoid valve
12A0105l EGR valve control vacuurr
16Normal state---H
Ln
12A0104
NOTEReplace the engine control unit if a malfunction code is output although the inspection reveals that there is no problem with the check
items.

14-68FUEL SYSTEM - MPI System Inspection <2.0L DOHC Engine>
MPI SYSTEM INSPECTION <2.0L DOHCCOMPONENTS LOCATION

Throttle
Dosition sensor
Crankshaft angle sensor
‘DC sensor
N14PAANIgnition timing adjustment terminal
Fuelpumpcheck terminal
I /B \ Q-terminalFuelpump check\Ignition timing adjustment terminal
Fuelpumpcheck terminal
ustment terminalir-flow sensor
takeair temperature sensor
arometric pressure sensornhibitor switch (A/T only)
OlA040i

14-70FUEL SYSTEM - MPI System Inspection <2.0L DOHC Engine>

Throttle position sensor
tm\ m24-T.\/ \Waste aate control valve [Turbo
only1
IO;A0455I nition timing adjustment terminal
9uel pump check terminal
----Fuel
pump checkAir-flow sensor
Intake air temperature sensor
BarometricDressure sensor
1 (built in intakeair’ Y/I
I
iemperature sensor andbarometricpressure sensor) Lsensor

14-72FUEL SYSTEM - MPI Svstem InsDection <2.0L DOHC Engine>
MALFUNCTION INDICATOR LIGHTAmong the self-diagnosis items, a malfunction indicator light
comes on to notify the driver of the emission control items
when an irregularity is detected.
However, when an irregular signal returns to normal and the
engine control unit judges that it has returned to normal. the
malfunction indicator light goes out.
Moreover, when the ignition switch is turned off, the light goes
out. Even if the ignition switch is turned on again, the light doesnot come on until the irregularity is detected.
Here, immediately after the ignition switch is turn on, the
malfunction indicator light is lit for 5 seconds to indicate that
the malfunction indicator light operates normally.
I--l
klfunctionindicator light
Items indicated by the lightening malfunction light
Engine control unit
Oxygen sensor
Air flow sensor
Intake air temperature sensor
Throttle positron sensor
Engrne coolant temperature sensor
Crank angle sensor
Top dead center sensor
Barometric pressure sensor
Detonatron sensor
Injector
Fuel pump
EGR
Ignition co11
/
iMALFUNCTION INDICATOR LIGHT INSPECTION
When turning on the ignition switch, check that the light comes
on.
NOTEIf the light does not come on, check the harness and light for
breakage.