Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 33

FU(STI)-44

Manifold Absolute Pressure Sensor

FUEL INJECTION (FUEL SYSTEMS)

4) Connect the Mighty Vac to the pressure port (A)

of manifold absolute pressure sensor.

5) Check the voltage when generating vacuum and

positive pressure using Mighty Vac.
CAUTION:

Do not apply vacuum of less than –88 — 200

kPa (–0.9 — 2.04 kgf/cm

2

, –12.8 — 29.0 psi). Do-

ing so may damage the manifold absolute pres-

sure sensor.
NOTE:

When vacuum occurs at the pressure port of man-

ifold absolute pressure sensor, the voltage will drop

from the value as in step 3). When positive pres-

sure occurs, on the other hand, the voltage will rise.

Pressure

Terminal No.

Standard

–88 kPa (–0.9 kgf/cm

2

,

–12.8 psi)

1 (+) and 2 (–)

Approx. 0.8 V

(when 25°C

(77°F))

181 kPa (1.85 kgf/cm

2

,

26.2 psi)

Approx. 4.7 V

(when 25°C

(77°F))

FU-04492

(A)

FU(STI)-45

Fuel Injector

FUEL INJECTION (FUEL SYSTEMS)

11.Fuel Injector

A: REMOVAL

1. RH SIDE

1) Release the fuel pressure. <Ref. to FU(STI)-67,

RELEASING OF FUEL PRESSURE, PROCE-

DURE, Fuel.>

2) Disconnect the ground cable from battery.

3) Open the fuel filler lid and remove the fuel filler

cap.

4) Remove the intake manifold. <Ref. to FU(STI)-

17, REMOVAL, Intake Manifold.>

5) Remove clip (A) holding the engine harness to

the fuel pipe protector RH, and remove the fuel

pipe protector RH from the intake manifold.

6) Remove the harness band (A) which holds the

engine harness to the fuel injector pipe RH.

7) Disconnect the connector from fuel injector.

8) Remove the bolts which hold fuel injector pipe

RH.

9) Remove the fuel injector.

IN-00203

FU-06575

(A)

FU-05919

(A)

FU-03568

FU-03512

FU-03513

FU(STI)-46

Fuel Injector

FUEL INJECTION (FUEL SYSTEMS)

2. LH SIDE

1) Release the fuel pressure. <Ref. to FU(STI)-67,

RELEASING OF FUEL PRESSURE, PROCE-

DURE, Fuel.>

2) Disconnect the ground cable from battery.

3) Open the fuel filler lid and remove the fuel filler

cap.

4) Remove the intake manifold. <Ref. to FU(STI)-

17, REMOVAL, Intake Manifold.>

5) Remove the fuel pipe protector LH from the in-

take manifold.

6) Remove the harness band (A) which holds the

engine harness to the fuel injector pipe LH.

7) Disconnect the connector from fuel injector.

8) Remove the bolts which hold fuel injector pipe

LH.

9) Remove the fuel injector.

IN-00203

FU-06591

FU-05920

(A)

FU-03508

FU-03594

FU-03595

FU-03527

FU(STI)-47

Fuel Injector

FUEL INJECTION (FUEL SYSTEMS)

B: INSTALLATION

1. RH SIDE

Install in the reverse order of removal.
NOTE:

Use new O-rings.
Tightening torque:

19 N·m (1.9 kgf-m, 14.0 ft-lb)

2. LH SIDE

Install in the reverse order of removal.
NOTE:

Use new O-rings.
Tightening torque:

6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

Tightening torque:

19 N·m (1.9 kgf-m, 14.0 ft-lb)

C: INSPECTION

1) Check that the fuel injector has no deformation,

cracks or other damages.

2) Measure the resistance between fuel injector

terminals.

FU-03512

FU-06583

FU-03594

Terminal No.

Standard

1 and 2

Approx. 12.0 Ω

(when 20°C (68°F))

FU-03595

FU-06584

2 1

EC-02428