Maeda MC815C, Руководство по обслуживанию, Страница: 349 / 378

T-403
1.2.1 TROUBLESHOOTING OF THE ENGINE UNIT
As a common cause of troubles in the engines, when none of the following symptoms does not apply, the
below-listed causes should be suspected:
• Faults in main body such as engine seizure caused by overload services or poor maintenance.
• Adverse effects of unauthorized components (such as radio receiver and lamps)
• Faulty grounding of ECM (engine controller) and CPU failure
S-1 [Engine start fault]
Symptom
Cranking revolution is low.
While cranking runs properly, engine does not start.
While engine starts, the engine revolution cannot be stabilized and maintained.
Assumed cause
and action to be
taken
Cause Diagnostic method and action to be taken
1 Fuel or oil abnormality
• Check to ensure that fuel is filled.
• Check to ensure that specified fuel and oil are used.
• Check the fuel for any sign of freezing. If frozen, replace it with
a low temperature-withstanding fuel.
• Check the fuel for any water inclusion.
2 Fault in fuel piping and filter
• Check fuel line for any air inclusion.
• Check fuel filter for any clogging.
• Check to make sure the fuel pump is running.
3 Battery capacity shortage
• Check if battery voltage has dropped.
Voltage (1 item): 12 V or more; Specific gravity (1 item): 1.26
or more
4 Intake system fault
• Check air cleaner for any clogging.
• Check air intake piping for any fault.
5 Electrical wiring fault • Check engine and fuel circuit.
6 Hydraulic unit fault
• Check to ensure that hydraulic pump functions properly and
there is no abnormality that may cause engine overload.
7 Supply pump fault
• Check the supply pump for fuel pressurization for any sign of
pump starting fault.
[Additional information]
Note on the use of unauthorized fuels:
• Using a low-viscosity fuel such as kerosene may cause a delivery failure because of accelerated abrasion
of supply pump plunger, resulting in a starting fault.
• Fuels preserved for a long time or mixed with a biofuel containing organic substances are prone to be
oxidized, and accelerate abrasion of camshaft-related parts inside the supply pump causing start fault due
to insufficient delivery.
• While replacement of supply pump is required in the case of fault mentioned above, continued use of
unauthorized fuels may recur the faults, and thus give guidance to the users to use specified fuel.