CITROEN C5 Handbook page 201

C5
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] = 0.8 ± 0.4 Bar.
Abnormal functioning
Fuel supply pressure
Between 3.3 and 4 Bar
More than 4 Bar
More than 4 Bar
Between 0.8 and 1.5 Bar
Impossible to start the engine :
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)
Check :
The flow should be drop by drop
Excessive fuel return
CHECKS : LOW PRESSURE FUEL SUPPLY CIRCUIT
Engines : RHY - RHS - RHZ - 4HX (Continued)
Fuel return pressure
0.8 ± 0.4 Bar
Less than 0.8 Bar
More than 0.8 Bar
Less than 0.8 Bar
Diesel injector functioning correctly
Diesel injector locked shut.
198
Check the condition of the diesel filter
Check the low pressure regulator incorporated in
the filter (locked shut) : replace.
Check the fuel return circuit (pipe pinched or trapped....).
Check the fuel suppy circuit :
- Booster pump (low pressure), piping.
Check : diesel injector return flow. (Table below)
Uncouple the diesel injector return pipe.
Notes
Checks