Troubleshooting; General - Mitsubishi S3L Service Manual

TROUBLESHOOTING

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OVERHAUL INSTRUCTIONS
OVERHAUL INSTRUCTIONS
6 TROUBLESHOOTING
6.1

General

The diagnosis of troubles, especially those caused by a
faulty fuel injection pump or injection nozzles, or low
compression pressure, can be difficult. It requires a
careful inspection to determine not which item is the
cause, but how may causes are contributing to the
trouble, someone of which is the primary cause.
Several causes may be contributing to a single trouble.
On the following pages, there are troubleshooting
charts on which engine troubles can be traced to their
causes. Each chart has items to be verified ahead and
suggested inspection procedure.
Diesel engines exhibit some marked characteristics
during operation. Knowing these characteristics will
help minimize time lost in tracing engine troubles to
their source. Following are the characteristics of diesel
engines you should know about for diagnosis:
• Combustion knock (diesel knock)
• Some black exhaust smoke (when the engine
picks up load)
• Vibration (due to high compression pressure and
high torque)
• Hunting (when the engine speed is quickly
decreased)
• Some white exhaust smoke (when the engine is
cold, or shortly after the engine has been started)
ENGLISH Service Manual Mitsubishi SL-Series diesel engines
Version 08/2004