Atlas Copco QAS 14, Instruction Manual

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Engine trouble shooting
The table below gives an overview of the possible
engine problems and their possible causes.
The starter motor turns the engine
too slowly
– Battery capacity too low.
– Bad electrical connection.
– Fault in starter motor.
– Wrong grade of lubricating oil.
The engine does not start or is
difficult to start
– Starter motor turns engine too slowly.
– Fuel tank empty.
– Fault in fuel control solenoid.
– Restriction in a fuel pipe.
– Fault in fuel lift pump.
– Dirty fuel filter element.
– Air in fuel system.
– Fault in atomisers.
– Cold start system used incorrectly.
– Fault in cold start system.
– Restriction in fuel tank vent.
– Wrong type or grade of fuel used.
– Restriction in exhaust pipe.
Not enough power
– Restriction in a fuel pipe.
– Fault in fuel lift pump.
– Dirty fuel filter element.
– Restriction in air filter/cleaner or induction
system.
– Air in fuel system.
– Fault in atomisers or atomisers of an incorrect
type.
– Restriction in fuel tank vent.
– Wrong type or grade of fuel used.
– Restricted movement of engine speed control.
– Restriction in exhaust pipe.
– Engine temperature is too high.
– Engine temperature is too low.
Misfire
– Restriction in a fuel pipe.
– Fault in fuel lift pump.
– Dirty fuel filter element.
– Air in fuel system.
– Fault in atomisers or atomisers of an incorrect
type.
– Fault in cold start system.
– Engine temperature is too high.
– Incorrect valve tip clearances.
The pressure of the lubricating oil is
too low
– Wrong grade of lubricating oil.
– Not enough lubricating oil in sump.
– Defective gauge.
– Dirty lubricating oil filter element.
High fuel consumption
– Restriction in air filter/cleaner or induction
system.
– Fault in atomisers or atomisers of an incorrect
type.
– Fault in cold start system.
– Wrong type or grade of fuel used.
– Restricted movement of engine speed control.
– Restriction in exhaust pipe.
– Engine temperature is too low.
– Incorrect valve tip clearances.