Navistar International DT 466 Diagnostic/Troubleshooting Manual page 268

264
Fuel Possible Causes
No fuel
• Low fuel level in fuel tank
• Debris in tank can cause high-restriction and low
fuel pressure.
• Inline fuel valve (if equipped) could be shut-off
Low fuel pressure
• Dirty filter element
• Debris or rust in fuel strainer
• Restriction from the fuel tank to the fuel filter
housing inlet can cause high-restriction and low
fuel pressure.
• Plugged supplemental filters or water separators
can cause high-restriction and low fuel pressure.
• Debris in tank can cause high-restriction and low
fuel pressure.
• A kinked or bent fuel supply line or a blocked
pickup tube can cause high-restriction and low
fuel pressure.
Aerated fuel
• Failed seal for inlet fitting in fuel filter housing
• Supply filter or water separator leaking
• A loose fuel line on the suction side of the fuel
system can ingest air into the system and cause
low fuel pressure (most noticeable under load).
• Strainer drain valve loose or damaged
Fuel restriction
• Dirty filter element
• Debris or rust in fuel strainer
• Restriction from the fuel filter housing inlet to
the fuel tank can cause high-restriction and low
fuel pressure.
• Plugged supplemental filters or water separators
can cause high-restriction and low fuel pressure.
• Debris in tank can cause high-restriction and low
fuel pressure.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
6 PERFORMANCE DIAGNOSTICS
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EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
Failed seals or fuel lines between fuel tanks
Ice in fuel lines
Inoperative fuel tank transfer pump
Fuel tank pickup tube cracked
Waxed or jelled fuel in the fuel filter will cause
high-restriction and low fuel pressure. (Usually
Grade 2-D)
Ice in fuel lines.
A restriction between the fuel inlet fitting, strainer,
and fuel pump can cause high-restriction and
low fuel pressure.
Debris in the fuel regulator valve
Failed fuel pressure regulator valve.
Failed fuel pump
Failed high-pressure oil pump (can not operate
fuel pump)
Strainer bowl warped or damaged
Missing O-ring from strainer bowl
Damaged seals on steel inlet tube to fuel pump
Primer pump seals damaged
A kinked or bent fuel supply line or a blocked
pickup tube can cause high-restriction and low
fuel pressure.
Waxed or jelled fuel in the fuel filter will cause
high-restriction and low fuel pressure. (Usually
Grade 2-D)
Ice in fuel lines.
A restriction between the fuel inlet fitting, strainer,
and fuel pump can cause high-restriction and
low fuel pressure.