ONL773LW4 5/21
24
Troubleshooting
ENGINE
PROBLEM
POSSIBLE CAUSE
RECOMMENDATION(S)
Engine Hard to Start
Improper starting procedure
• See starting section of this manual. Take
or Will Not Start
special note of Bypass Switch operation.
No fuel
• Check level of fuel in fuel tank.
Low battery output
• Check electrolyte level and condition.
Excessive resistance
• Clean and tighten all battery connections.
in starting circuit
Crankcase oil too heavy
• Use oil of proper viscosity.
Improper type of fuel
• Consult fuel supplier and use proper type
of fuel for operating condition.
Water, dirt or air in fuel system
• Drain, flush, fill and bleed system.
Clogged primary
• Clean or replace filter element.
fuel filter element
Lift pump malfunction
• Repair lift pump.
Clogged secondary
• Replace filter element.
fuel filter element
Dirty or faulty injection nozzles
• Have your dealer check injection nozzles.
Uneven compression pressure
• Check cylinder compression pressure.
between cylinders.
Engine Runs Irregularly
Below normal engine temperature • Remove and check thermostat.
or Stalls Frequently
Clogged primary
• Clean or replace filter element.
fuel filter element
Clogged secondary
• Replace secondary filter element.
fuel filter element
Water or dirt in the fuel system
• Drain, flush, fill and bleed system.
Dirty or faulty injection nozzles
• Have your dealer check injection nozzles.
Air in fuel system
• Inspect clamps and hoses on suction side
of fuel pump for air leak.
Improper type of fuel
• Consult fuel supplier and use proper type
of fuel for operating condition.
Lack of Engine Power
Intake air restriction
• Service air cleaner, check proper ventilation.
Clogged primary
• Clean or replace filter element.
fuel filter element
Clogged secondary
• Replace filter element.
fuel filter element
Injection pump not getting fuel
• Have injection pump checked.
Improper type of fuel
• Consult fuel supplier and use proper type of
fuel for operating conditions.
