2004 SUBARU FORESTER engine

EN(H4SO)-255
ENGINE (DIAGNOSTIC)
General Diagnostic Table
20.General Diagnostic Table
A: INSPECTION
1. ENGINE
NOTE:
Malfunction of parts other than those listed is also possible. eral.>
Symptom Problem parts
1. Engine stalls during idling.1) Idle air control solenoid valve
2) Manifold absolute pressure sensor
3) Intake air temperature sensor
4) Ignition parts (*1)
5) Engine coolant temperature sensor (*2)
6) Crankshaft position sensor (*3)
7) Camshaft position sensor (*3)
8) Fuel injection parts (*4)
2. Rough idling1) Idle air control solenoid valve
2) Manifold absolute pressure sensor
3) Intake air temperature sensor
4) Engine coolant temperature sensor (*2)
5) Ignition parts (*1)
6) Air intake system (*5)
7) Fuel injection parts (*4)
8) Throttle position sensor
9) Crankshaft position sensor (*3)
10) Camshaft position sensor (*3)
11) Oxygen sensor
12) Fuel pump and fuel pump relay
3. Engine does not return to idle.1) Idle air control solenoid valve
2) Engine coolant temperature sensor
3) Accelerator cable (*6)
4) Throttle position sensor
5) Manifold absolute pressure sensor
6) Intake air temperature sensor
4. Poor acceleration1) Manifold absolute pressure sensor
2) Intake air temperature sensor
3) Throttle position sensor
4) Fuel injection parts (*4)
5) Fuel pump and fuel pump relay
6) Engine coolant temperature sensor (*2)
7) Crankshaft position sensor (*3)
8) Camshaft position sensor (*3)
9) A/C switch and A/C cut relay
10) Engine torque control signal circuit
11) Ignition parts (*1)
5. Engine stalls or engine sags or hesitates at
acceleration.1) Manifold absolute pressure sensor
2) Intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Crankshaft position sensor (*3)
5) Camshaft position sensor (*3)
6) Purge control solenoid valve
7) Fuel injection parts (*4)
8) Throttle position sensor
9) Fuel pump and fuel pump relay

EN(H4SO)-256
ENGINE (DIAGNOSTIC)
General Diagnostic Table
*1: Check ignition coil & ignitor ASSY and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure the secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect air leak in air intake system.
*6: Adjust the accelerator cable.
2. AUTOMATIC TRANSMISSION
NOTE:
Check general diagnostics table with non-conformity symptom for automatic transmission. 4AT(H4SO)-2, Basic Diagnostic Procedure.>
6. Surging1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Crankshaft position sensor (*3)
6) Camshaft position sensor (*3)
7) Fuel injection parts (*4)
8) Throttle position sensor
9) Fuel pump and fuel pump relay
7. Spark knock1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor
5) Knock sensor
6) Fuel injection parts (*4)
7) Fuel pump and fuel pump relay
8. After burning in exhaust system1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay Symptom Problem parts

FUJI HEAVY INDUSTRIES LTD. G8080GE3
2004 FORESTER SERVICE MANUAL QUICK REFERENCE INDEX
ENGINE SECTION 2
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.FUEL INJECTION (FUEL SYSTEM) FU(H4DOTC)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICE)EC(H4DOTC)
INTAKE (INDUCTION) IN(H4DOTC)
MECHANICAL ME(H4DOTC)
EXHAUST EX(H4DOTC)
COOLING CO(H4DOTC)
LUBRICATION LU(H4DOTC)
SPEED CONTROL SYSTEM SP(H4DOTC)
IGNITION IG(H4DOTC)
STARTING/CHARGING SYSTEM SC(H4DOTC)
ENGINE (DIAGNOSTIC) EN(H4DOTC)

FUEL INJECTION (FUEL SYSTEM)
FU(H4DOTC)
Page
1. General Description ....................................................................................2
2. Throttle Body .............................................................................................13
3. Intake Manifold ..........................................................................................14
4. Engine Coolant Temperature Sensor........................................................29
5. Crankshaft Position Sensor.......................................................................30
6. Camshaft Position Sensor.........................................................................31
7. AVCS Camshaft Position Sensor ..............................................................32
8. Knock Sensor ............................................................................................33
9. Throttle Position Sensor ............................................................................34
10. Mass Air Flow and Intake Air Temperature Sensor ..................................35
11. Manifold Absolute Pressure Sensor ..........................................................36
12. Idle Air Control Solenoid Valve .................................................................37
13. Fuel Injector ..............................................................................................38
14. Tumble Generator Valve Assembly ..........................................................42
15. Tumble Generator Valve Actuator.............................................................43
16. Wastegate Control Solenoid Valve Assembly ...........................................44
17. Front Oxygen (A/F) Sensor .......................................................................45
18. Rear Oxygen Sensor.................................................................................47
19. Exhaust Temperature Sensor ...................................................................49
20. Engine Control Module (ECM) ..................................................................50
21. Main Relay ................................................................................................51
22. Fuel Pump Relay.......................................................................................52
23. Fuel Pump Control Unit .............................................................................53
24. Fuel ...........................................................................................................54
25. Fuel Tank ..................................................................................................55
26. Fuel Filler Pipe ..........................................................................................58
27. Fuel Pump .................................................................................................62
28. Fuel Level Sensor .....................................................................................64
29. Fuel Sub Level Sensor ..............................................................................65
30. Fuel Filter ..................................................................................................67
31. Fuel Cut Valve...........................................................................................68
32. Fuel Damper Valve ...................................................................................69
33. Fuel Delivery, Return and Evaporation Lines............................................70
34. Fuel System Trouble in General ...............................................................73

FU(H4DOTC)-13
FUEL INJECTION (FUEL SYSTEM)
Throttle Body
2. Throttle Body
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the intercooler. 10, REMOVAL, Intercooler.>
3) Disconnect the connector from the throttle posi-
tion sensor (A) and idle air control solenoid valve
(B) and manifold absolute pressure sensor (C).
4) Disconnect the accelerator cable.
5) Disconnect the engine coolant hoses from throt-
tle body.6) Remove the bolts which secure the throttle body
to intake manifold.B: INSTALLATION
1) Install in the reverse order of removal.
NOTE:
Always use a new gasket.
Tightening torque:
22 N
⋅m (2.2 kgf-m, 16.2 ft-lb)
2) Adjust the accelerator cable play. SP(H4SO)-9, INSTALLATION, Accelerator Control
Cable.>
FU-00009
(A)(B)
(C)
FU-00010
FU-00011
FU-00012
FU-00013

FU(H4DOTC)-15
FUEL INJECTION (FUEL SYSTEM)
Intake Manifold
(6) Place the power steering pump on right side
wheel apron.
13) Disconnect the emission hose from PCV valve.
14) Disconnect the engine coolant hoses from
throttle body.
15) Disconnect the brake booster hose.16) Disconnect the pressure hose from intake duct.
17) Disconnect the engine harness connectors
from bulkhead harness connectors.
18) Disconnect the connectors from the engine
coolant temperature sensor (A), oil pressure switch
(B) and crankshaft position sensor (C).
FU-00021
FU-00022
FU-00012
FU-00023
FU-00024
FU-00025
FU-02086
(A)
(B)
(C)
FU-00027

FU(H4DOTC)-16
FUEL INJECTION (FUEL SYSTEM)
Intake Manifold
19) Disconnect the knock sensor connector.
20) Disconnect the connector from crankshaft posi-
tion sensor.
21) Disconnect the connector from camshaft posi-
tion sensor.
22) Disconnect the connector from AVCS camshaft
position sensor.23) Disconnect the connector from oil flow control
solenoid valve.
24) Disconnect the connector from ignition coil.
25) Disconnect the engine harness fixed by clip (A)
from bracket.
FU-00028
FU-00029
FU-00059
FU-00061
ME-00711
FU-00030
FU-00031
(A)

FU(H4DOTC)-18
FUEL INJECTION (FUEL SYSTEM)
Intake Manifold
4) Connect the connector to the oil pressure switch
(B), crankshaft position sensor (C) and engine
coolant temperature sensor (A).
5) Connect the connector to knock sensor.
6) Connect the connector to crankshaft position
sensor.
7) Connect the connector to camshaft position sen-
sor.8) Connect the connector to AVCS camshaft posi-
tion sensor.
9) Connect the connector to oil flow control sole-
noid valve.
10) Connect the connector to ignition coil.
11) Connect the engine harness with clip (A) to the
bracket.
(A)
(B)
(C)
FU-00027
FU-00028
FU-00029
FU-00059
FU-00061
ME-00711
FU-00030
FU-00031
(A)