CHECKS : LOW PRESSURE FUEL SUPPLY CIRCUIT
XANTIA - SYNERGIE
Engines : RHZ - RHY (continued)
Checks on pressure : dynamic.
Engine running, at idle (normal functioning):
- Fuel supply pressure shown by the pressure gauge [3] = 2 ± 0.4 Bar.
- Fuel return pressure shown by the pressure gauge [3] = 0.7 ± 0.4 Bar.
Abnormal functioning
Fuel supply pressure
Fuel return pressure
Checks
Between 3 and 3.5 Bar
0.7 ± 0.2 Bar
Check the condition of the diesel filter
Check the low pressure regulator incorporated in
More than 3.5 Bar
More than 3.5 Bar
Less than 0.7 Bar
More than 0.7 Bar
Less than 0.7 Bar
the filter (locked shut) : replace.
Check the fuel return circuit (pipe pinched or trapped...).
Check the fuel suppy circuit :
- Booster pump (low pressure), piping.
Between 0.8 and 1.5 Bar
Impossible to start the engine :
Check : diesel injector return flow. (Table below)
Fuel supply pressure less than 0.8 Bar :
- Check the low pressure regulator incorporated in the filter (locked open).
- Check the high pressure pump distribution valve (locked shut).
Uncouple the diesel injector return pipe.
Check :
The flow should be drop by drop.
Excessive fuel return.
Observe :
Diesel injector functioning correctly.
Diesel injector locked shut.
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