Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 138

FU(w/o STI)-79

Fuel Pump

FUEL INJECTION (FUEL SYSTEMS)

B: INSTALLATION

Install in the reverse order of removal while being

careful of the following.

• Make sure the sealing portion is free from fuel or

foreign matter before installation.

• Align protrusion (A) of the gasket to the position

shown in the figure.

• Insert the protrusion (B) of gasket to the fuel

pump upper plate. (3 places)

• Align the protrusion (C) of fuel pump assembly

with the cutout on the fuel pump upper plate.

• Tighten the nuts to the specified torque in the or-

der as shown in the figure.
NOTE:

Use a new gasket.
Tightening torque:

4.4 N·m (0.4 kgf-m, 3.2 ft-lb)

C: INSPECTION

1) Check that the fuel pump has no deformation,

cracks or other damages.

2) Connect the battery positive terminal to terminal

No. 5 and the battery ground terminal to terminal

No. 6, and inspect the fuel pump operation.
WARNING:

• Wipe off fuel completely.

• Keep the battery as far apart from fuel pump

as possible.

• Do not run the fuel pump for a long time un-

der non-load condition.

(a) Front side of vehicle

FU-04532

1

2

3

4

5

6

7

8

(C)

(B)

(B)

(B)

(A)

(a)

FU-04110

2 1
4 3
6 5

FU(w/o STI)-80

Fuel Level Sensor

FUEL INJECTION (FUEL SYSTEMS)

27.Fuel Level Sensor

A: REMOVAL

WARNING:

Place “NO OPEN FLAMES” signs near the

working area.
CAUTION:

• Be careful not to spill fuel.

• If the fuel gauge indicates that two thirds or

more of the fuel is remaining, be sure to drain

fuel before starting work to avoid the fuel to

spill.
NOTE:

The fuel level sensor is built in fuel pump assembly.

1) Remove the fuel pump assembly. <Ref. to FU(w/

o STI)-78, REMOVAL, Fuel Pump.>

2) Disconnect the fuel level sensor connector.

3) Slide the fuel level sensor in the direction of the

arrow and remove the fuel level sensor by pressing

the claw (A) of the fuel level sensor.

B: INSTALLATION

Install in the reverse order of removal.

C: INSPECTION

1) Check that the fuel level sensor has no damage.

2) Measure the fuel level sensor float position.
NOTE:

When inspecting the fuel level sensor, perform the

work with the sensor installed to the fuel pump.

3) Measure the resistance between fuel level sen-

sor terminals.

FU-04223

FU-04224

(A)

(1) FULL
(2) EMPTY
(3) Fuel tank seating surface

Float position

Standard

FULL to Fuel tank seating

surface (A)

135±4 mm (5.315±0.157 in)

EMPTY to Fuel tank seating

surface (B)

23.7±4 mm (0.933±0.157 in)

Float position

Terminal No.

Standard

FULL (A)

1 and 4

2.0±1.0 Ω

EMPTY (B)

31.9±1.0 Ω

FU-04229

(1)

(A)

(3)

(B)

(2)

FU-04230

2 1
4 3
6 5

(B)

(A)

FU(w/o STI)-81

Fuel Sub Level Sensor

FUEL INJECTION (FUEL SYSTEMS)

28.Fuel Sub Level Sensor

A: REMOVAL

WARNING:

Place “NO OPEN FLAMES” signs near the

working area.
CAUTION:

• Be careful not to spill fuel.

• Catch the fuel from the tubes using a contain-

er or cloth.

• If the fuel gauge indicates that two thirds or

more of the fuel is remaining, be sure to drain

fuel before starting work to avoid the fuel to

spill.

1) Release the fuel pressure. <Ref. to FU(w/o STI)-

65, RELEASING OF FUEL PRESSURE, PROCE-

DURE, Fuel.>

2) Drain fuel. <Ref. to FU(w/o STI)-65, DRAINING

FUEL (WITH SUBARU SELECT MONITOR),

PROCEDURE, Fuel.>

3) Disconnect the ground cable from battery.

4) Remove the rear seat cushion. <Ref. to SE-13,

REMOVAL, Rear Seat.>

5) Remove the service hole cover.

6) Disconnect the connector from the fuel sub level

sensor.

7) Disconnect the quick connectors of fuel delivery

tube (A), fuel return tube (B), and jet pump tube (C).

<Ref. to FU(w/o STI)-89, REMOVAL, Fuel Deliv-

ery, Return and Evaporation Lines.>

8) Remove the rubber cap (D) from the nut.

9) Remove the bolts and nuts which hold fuel sub

level sensor protector and fuel sub level sensor up-

per plate to the fuel tank.

10) Remove the fuel sub level sensor from the fuel

tank.

IN-00203

FU-06553

FU-03364

FU-04239

(A)

(B)

(C)

(D)

FU-01146

FU-04569

FU(w/o STI)-82

Fuel Sub Level Sensor

FUEL INJECTION (FUEL SYSTEMS)

B: INSTALLATION

Install in the reverse order of removal while being

careful of the following.

• Make sure the sealing portion is free from fuel or

foreign matter before installation.

• Align protrusion (A) of the gasket to the position

shown in the figure.

• Align protrusion (B) of the fuel sub level sensor to

the cutout in the fuel sub level sensor upper plate.

• Tighten the nuts and bolts to the specified torque

in the order as shown in the figure.

• After tightening, install the rubber cap (C) at the

position shown in the figure.
NOTE:

• Use a new gasket.

• Do not forget to install rubber cap (C).
Tightening torque:

4.4 N·m (0.4 kgf-m, 3.2 ft-lb)

C: INSPECTION

1) Check that the fuel sub level sensor has no dam-

age.

2) Measure the fuel sub level sensor float position.

3) Measure the resistance between fuel sub level

sensor terminals.

(a) Front side of vehicle

FU-04533

1

6

5

2

4

3

(B)

(A)

(a)

FU-04242

(C)

(1) FULL
(2) EMPTY
(3) Datum points

Float position

Standard

FULL to Datum point (A)

5.31±3.5 mm (0.209±0.138 in)

EMPTY to Datum point (B) 160.6±3.5 mm (6.323±0.138 in)

Float position

Terminal No.

Standard

FULL (A)

1 and 2

2.0

+0.5

–1.0

Ω

EMPTY (B)

62.1±1.0 Ω

(1)

(B)

(2)

(A)

FU-04213

(3)

FU-04214

2 1

(B)

(A)