Subaru Impreza 2003, Service Manual

Page: 196 / 3610

FU(H4SO)-68
FUEL INJECTION (FUEL SYSTEMS)
FUEL SYSTEM TROUBLE IN GENERAL
29.Fuel System Trouble in General
A: INSPECTION
NOTE:
• When the vehicle is left unattended for an ex-
tended period of time, water may accumulate in the
fuel tank.
To prevent water condensation.
(1) Top off the fuel tank or drain the fuel com-
pletely.
(2) Drain the water condensation from the fuel
filter.
• Refilling the fuel tank.
Refill the fuel tank while there is still some fuel left in
the tank.
• Protecting the fuel system against freezing and
water condensation.
(3) Cold areas:
In snow-covered areas, mountainous areas, ski-
ing areas, etc. where ambient temperatures
drop below 0
°
C (32
°
F) throughout the winter
season, use an anti-freeze solution in the cool-
ing system. Refueling will also complement the
effect of anti-freeze solution each time the fuel
level drops to about one-half. After the winter
season, drain the water which may have accu-
mulated in the fuel filter and fuel tank in the man-
ner same as that described under “Affected
areas” below.
(4) Affected areas:
When the water condensation is notched in the
fuel filter, drain the water from both the fuel filter
and fuel tank or use a water removing agent (or
anti-freeze solution) in the fuel tank.
• Observe the instructions, notes, etc., indicated
on the label affixed to the anti-freeze solution (wa-
ter removing agent) container before use.
Trouble and possible cause Corrective action
1. Insufficient fuel supply to the injector
1) Fuel pump will not operate.
❍
Defective terminal contact.
Inspect connections, especially ground, and tighten
securely.
❍
Trouble in electromagnetic or electronic circuit parts. Replace the fuel pump.
2) Lowering of fuel pump function. Replace the fuel pump.
3) Clogged dust or water in the fuel filter. Replace the fuel filter, clean or replace fuel tank.
4) Clogged or bent fuel pipe or hose. Clean, correct or replace the fuel pipe or hose.
5) Air is mixed in the fuel system. Inspect or retighten each connection part.
6) Clogged or bent breather tube or pipe. Clean, correct or replace the air breather tube or pipe.
7) Damaged diaphragm of pressure regulator. Replace.
2. Leakage or blow out fuel
1) Loosened joints of the fuel pipe. Retightening.
2) Cracked fuel pipe, hose and fuel tank. Replace.
3) Defective welding part on the fuel tank. Replace.
4) Defective drain packing of the fuel tank. Replace.
5) Clogged or bent air breather tube or air vent tube.
Clean, correct or replace the air breather tube or air vent
tube.
3. Gasoline smell inside of compartment
1)
Loose joints at air breather tube, air vent tube and fuel
filler pipe.
Retightening.
2) Defective packing air tightness on the fuel saucer. Correct or replace the packing.
3) Cracked fuel separator. Replace the separator.
4) Inoperative fuel pump modulator or circuit. Replace.
4. Defective fuel meter indicator
1) Defective operation of fuel level sensor. Replace.
2) Defective operation of fuel meter. Replace.
5. Noise
1) Large operation noise or vibration of fuel pump. Replace.