WP13 Diesel Engine Series Operating Manual
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(4) The crankshaft and camshaft signals are missing
On the diesel engine, there are two speed sensors mounted respectively outside the flywheel
housing and the high-pressure fuel pump. The functions are respectively shown as follows: the
crankshaft position sensor and cylinder identification sensor will decide the fuel injection timing of
electronic control engine, and if a diesel engine cannot be started, such two signals have been
missing.
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Possible causes for missing of the two signals
(1) The sensors are damaged and their harnesses are open or short circuit
(2) Excessively larger or smaller clearance (usually 1mm ± 0.5mm) appears between the sensors
and the induction gears due to poor connection of the sensors.
Troubleshooting: check whether the sensors are damaged, whether the wire harness is well
connected, and whether the sensors are loose.
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After disassembly, the high-pressure fuel pump and the flywheel should be installed in strict
accordance with the relevant technical documents to ensure synchronization of the signals.
6.2.2 Difficult to Start
Reason and Troubleshooting of the difficulty in engine starting:
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The diesel engine hasn’t been working for a long time: Stretch the fuel return pipe under the
diesel fuel surface.
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The low-pressure pipeline has a small amount of air: Exhaust the air.
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The crankshaft and camshaft have too weak speed signals, resulting in longer time for
synchronous judgment: Find out the specific reasons and make readjustment.
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The ambient temperature is too low, resulting in failure of the preheating device: check
whether the heating flange wiring is normal or replace the preheating device.
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The diesel fuel and engine oil is too poor in quality and not up to the standard: Use standard
fuel and oil instead.
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The starter or flywheel has ring gears hitting: replace the starter and the flywheel ring gears.
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The piston rings and cylinder liners are worn or the valves are not sealed tightly: replace the
piston rings, cylinder liners or valve seats and valves.
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The exhaust brake butterfly valve is stuck at its “Off” state, resulting in poor exhaust: replace
the butterfly valve.
Crankshaft speed sensor
Camshaft speed sensor
