Mitsubishi Lancer Evolution IX. Manual — part 480

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI)

13A-395

ON-VEHICLE SERVICE

THROTTLE BODY (THROTTLE VALVE
AREA) CLEANING

M1131001000990

1. Remove the air intake hose from the throttle body.
2. Spray cleaning fluid on a clean cloth.

CAUTION

• Do not spray the cleaning fluid directly to the

throttle valve.

• Make sure the cleaning fluid does not enter

the motor from the bypass line. Also make
sure it does not enter the sensor through the
shaft.

• Be careful not to rub off the molybden applied

around the throttle valve shaft.

3. Wipe off the dirt around the throttle valve with the

cloth sprayed with cleaning fluid.

4. Attach the air intake hose.
5. Adjust the basic idle speed (Refer to

P.13A-396

).

THROTTLE POSITION SENSOR
ADJUSTMENT

M1131001100801

1. Connect the M.U.T.-II/III to the diagnosis

connector.
When not using the M.U.T.-II/III, proceed as
follows.

(1) Disconnect the throttle position sensor

connector and connect the special tool test
harness (MB991536) between the
disconnected connector taking care not to
confuse the terminal to be connected.

(2) Connect digital voltmeter between the terminal

No. 2 (special tool’s yellow clip on the sensor
output) and the terminal No. 4 (special tool’s
red clip on the sensor earth) of the throttle
position sensor connector.

2. Turn the ignition switch to "ON" position (but do

not start the engine).

3. Check the output voltage of the throttle position

sensor.

Standard value: 535

− 735 mV

4. If not within the standard value, loosen the throttle

position sensor mounting bolts. Then rotate the
sensor body to adjust.

5. Turn the ignition switch to "LOCK" (OFF) position.
6. Remove the M.U.T.-II/III. If the M.U.T.-II/III is not

used, remove the special tool, and then connect
the throttle position sensor connector.

7. If a diagnosis code is displayed, erase the

diagnosis code by using the M.U.T.-II/III or
disconnect the negative battery cable from the
battery terminal and then leave it for at least 10
seconds. After that, reconnect the battery cable,
and then let the engine run at idle for
approximately 10 minutes.

AK000833AD

15 mm

15 mm

Areas on throttle valve to
apply molybdenum disulfide

AK304568

1

2 3

4

AB

Equipment
side connector

Throttle
position sensor

AK201752AB

MB991536

Throttle position
sensor

AK304569AB

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI)

13A-396

BASIC IDLE SPEED ADJUSTMENT

M1131001800888

CAUTION

• The standard idling speed has been adjusted

by the speed adjusting screw (SAS) by the
manufacturer, and there should usually be no
need for readjustment.

• If the adjustment has been changed by mis-

take, the idle speed may become too high or
the idle speed may drop too low when loads
from components such as the A/C are placed
on the engine. If this occurs, adjust by the fol-
lowing procedure.

• The adjustment, if made, should be made

after first confirming that the spark plugs, the
injectors, the idle speed control servo, the
compression pressure, etc., are all normal.

1. Before inspection and adjustment, set the vehicle

to the pre-inspection condition.

2. Connect the M.U.T.-II/III to the diagnosis

connector (16-pin).
NOTE: When the M.U.T.-II/III is connected, the
diagnosis control terminal should be earthed.

3. Start the engine and run at idle.
4. Select the item No. 30 of the M.U.T.-II/III Actuator

test.
NOTE: This holds the idle speed control servo at
the basic step to adjust the basic idle speed.

5. Check the idle speed.

Standard value:

800

± 50 r/min

NOTE:

.

•

The engine speed may be 20 to 100 r/min
lower than indicated above for a new vehicle
[driven approximately 500 km or less], but no
adjustment is necessary.

•

If the engine stalls or the engine speed is low
even though the vehicle has been driven
approximately 500 km or more, it is probable
that deposits are adhered to the throttle valve,
so clean it (Refer to

P.13A-395

).

6. If not within the standard value range, turn the

speed adjusting screw (SAS) to make the
necessary adjustment.
NOTE: If the idling speed is higher than the stand-
ard value range even when the SAS is fully
closed, check whether or not there is any indica-
tion that the fixed SAS has been moved. If there is
an indication that it has been moved, adjust the
fixed SAS.

7. Press the M.U.T.-II/III clear key, and release the

idle speed control servo from the Actuator test
mode.
NOTE: Unless the idle speed control servo is
released, the Actuator test mode will continue 27
minutes.

8. Turn the ignition switch to "LOCK" (OFF) position.
9. Disconnect the M.U.T.-II/III.
10.Start the engine again and let it run at idle speed

for about 10 minutes; check that the idling
condition is normal.

FUEL PRESSURE TEST

M1131001901286

1. Release residual pressure from the fuel pipe line

to prevent fuel gush out (Refer to

P.13A-398

).

CAUTION

Cover the hose connection with rags to prevent
splash of fuel that could be caused by some
residual pressure in the fuel pipe line.

2. Disconnect the high-pressure fuel hose at the

delivery pipe side.

AK304570 AB

Speed adjust screw

AK304571AB

High-pressure
fuel hose

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI)

13A-397

3. Assemble the fuel pressure measurement tools

as follows.

<When using the fuel pressure gauge set (special

tool)>

a. Remove the union joint and bolt from the special

tool adaptor hose (MD998709) and attach the
special tool hose adaptor (MD998742) to the
adaptor hose.

b. Via a gasket, install the special tool fuel pressure

gauge set (MB991637 or MB991981) into the
special tool that has already assembled as
described in (a) above.

<When using the fuel pressure gauge>

a. Remove the union joint and bolt from special tool

adaptor hose (MD998709) and attach the special
tool hose adaptor (MD998742) to the adaptor
hose.

b. Via a suitable O-ring or gasket, install the fuel

pressure gauge to the special tool that has
already assembled as described in (a) above.

4. Install the assembled fuel pressure measurement

tools between the fuel rail and fuel high-pressure
hose.

CAUTION

To prevent damage to the M.U.T.-II/III, always turn
the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting the
M.U.T.-II/III.
5. Connect the M.U.T.-II/III to the diagnosis

connector.

6. Turn the ignition switch to "ON" position (But do

not start the engine).

7. Select "Item No. 07" from the M.U.T.-II/III Actuator

test to drive the fuel pump. Check that there are
no fuel leaks from any parts.

8. Finish the actuator test or turn the ignition switch

to "LOCK" (OFF) position.

9. Start the engine and run at idle.
10.Measure fuel pressure while the engine is running

at idle.

Standard value: Approximately 230 kPa

11.Disconnect the vacuum hose from the fuel

pressure regulator and measure fuel pressure
with the hose end closed by a finger.

Standard value: 289

− 309 kPa

12.Check to see that fuel pressure at idle does not

drop even after the engine has been raced
several times.

AKX01458 AG

MB 991637

Gasket

MD 998709

MD 998742

High-pressure
fuel hose

Delivery
pipe

AK305430AB

MB 991981

Gasket

MD 998709

MD 998742

High-pressure
fuel hose

Delivery
pipe

AKX01457AF

MD 998742

MD 998709

O-ring or gasket

Fuel pressure
gauge set

High-pressure
fuel hose

Delivery
pipe

AK304572AB

Vacuum hose

Fuel pressure
regulator

ON-VEHICLE SERVICE

MULTIPORT FUEL INJECTION (MPI)

13A-398

13.Racing the engine repeatedly, hold the fuel return

hose lightly with fingers to feel that fuel pressure
is present in the return hose.
NOTE: If the fuel flow rate is low, there will be no
fuel pressure in the return hose.

14.If any of fuel pressure measured in steps 10 to 13

is out of specification, troubleshoot and repair
according to the table below.

15.Stop the engine and check change of fuel

pressure gauge reading. Normal if the reading
does not drop within 2 minutes. If it does, observe
the rate of drop and troubleshoot and repair
according to the table below.

16.Release residual pressure from the fuel pipe line

(Refer to

P.13A-398

).

CAUTION

Cover the hose connection with rags to prevent
splash of fuel that could be caused by some
residual pressure in the fuel pipe line.
17.Remove the fuel pressure gauge and special tool

from the delivery pipe.

18.Replace the O-ring at the end of the fuel high

pressure hose with a new one. Furthermore,
apply engine oil to the new O-ring before
replacement.

19.Fit the fuel high pressure hose over the delivery

pipe and tighten the bolt to specified toque.

Tightening torque: 5.0

± 1.0 N⋅m

20.Check for any fuel leaks by following the

procedure in step 7.

21.Disconnect the M.U.T.-II/III.

FUEL PUMP CONNECTOR
DISCONNECTION (HOW TO REDUCE
PRESSURIZED FUEL LINES)

M1131000900718

WARNING

When removing the fuel pipe, etc., release
fuel pressure to prevent fuel spray.

1. Remove the rear seat assembly (Refer to GROUP

52A

− Rear Seat Assembly

P.52A-20

).

2. Remove the protector.

Symptom

Probable cause

Remedy

• Fuel pressure too low

• Fuel pressure drops after racing

• No fuel pressure in fuel return

hose

Clogged fuel filter

Replace fuel filter

Fuel leaking to return side due to
poor fuel regulator valve seating or
settled spring

Replace fuel pressure regulator

Low fuel pump delivery pressure

Replace fuel pump

Fuel pressure too high

Binding valve in fuel pressure
regulator

Replace fuel pressure regulator

Clogged fuel return hose or pipe

Clean or replace hose or pipe

Same fuel pressure when vacuum
hose is connected and when
disconnected

Damaged vacuum hose or
Clogged nipple

Replace vacuum hose or clean
nipple

Symptom

Probable cause

Remedy

Fuel pressure drops gradually after
engine is stopped

Leaky injector

Replace injector

Leaky fuel regulator valve seat

Replace fuel pressure regulator

Fuel pressure drops sharply
immediately after engine is
stopped

Check valve in fuel pump is held
open

Replace fuel pump

Y0915AU

Y2015AU

AC208407

Fuel pump module connector

AB