Fuel System Trouble In General - Subaru Legacy 2003 Service Manual

29.Fuel System Trouble in General

A: INSPECTION
Trouble and possible cause
1. Insufficient fuel supply to the injector
1) Fuel pump will not operate.
Defective terminal contact.
Trouble in electromagnetic or electronic circuit parts.
2) Lowering of fuel pump function.
3) Clogged dust or water in the fuel filter.
4) Clogged or bent fuel pipe or hose.
5) Air is mixed in the fuel system.
6) Clogged or bent breather tube or pipe.
7) Damaged diaphragm of pressure regulator.
2. Leakage or blow out fuel
1) Loosened joints of the fuel pipe.
2) Cracked fuel pipe, hose and fuel tank.
3) Defective welding part on the fuel tank.
4) Defective drain packing of the fuel tank.
5) Clogged or bent air breather tube or air vent tube.
3. Gasoline smell inside of compartment
Loose joints at air breather tube, air vent tube and fuel
1)
filler pipe.
2) Defective packing air tightness on the fuel saucer.
3) Cracked fuel separator.
4) Inoperative fuel pump modulator or circuit.
4. Defective fuel meter indicator
1) Defective operation of fuel meter unit.
2) Defective operation of fuel meter.
5. Noise
1) Large operation noise or vibration of fuel pump.
NOTE:
• When the vehicle is left unattended for an extended period of time, water may accumulate in the fuel tank.
To prevent water condensation.
(1) Top off the fuel tank or drain the fuel completely.
(2) Drain 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.
(1) Cold areas
In snow-covered areas, mountainous areas, skiing areas, etc. where ambient temperatures drop below
0°C (32°F) throughout the winter season, use an anti-freeze solution in the cooling 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 water which may have accumulated in the fuel filter and fuel tank in the manner
same as that described under Affected areas below.
(2) Affected areas
When water condensation is notched in the fuel filter, drain 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 (water remov-
ing agent) container before use.
FUEL SYSTEM TROUBLE IN GENERAL
FU(H4SO)-73
FUEL INJECTION (FUEL SYSTEMS)
Corrective action
Inspect connections, especially ground, and tighten
securely.
Replace the fuel pump.
Replace the fuel pump.
Replace the fuel filter, clean or replace the fuel tank.
Clean, correct or replace the fuel pipe or hose.
Inspect or retighten each connection part.
Clean, correct or replace the air breather tube or pipe.
Replace.
Retightening.
Replace.
Replace.
Replace.
Clean, correct or replace the air breather tube or air vent
tube.
Retightening.
Correct or replace packing.
Replace the separator.
Replace.
Replace.
Replace.
Replace.