2005 Citroen C4 Injector

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INJECTION
CHECKS: LOW PRESSURE FUEL SUPPLY CIRCUIT
Tools.
[1] Ø 10 mm low pressure connector: 4215-T
[2] Ø 8 mmlow pressure connector: 4218-T
[3]Pressure gauge for testing boost pressure: 4073-T Kit 4073-T
Connect the tool [1]between the booster pump and the fuel filter
(white mark at "a" on the fuel
supply pipe).
Connect the tool [2]downstream of the diesel injectors, between the high pressure fuel pump and
the fuel filter
(green mark at "b" on the fuel return pipe).
WARNING: Any check of pressure downstream of the fuel filter is PROHIBITED.
Checks on pressure: static.
- Switch on ignition.
For 3 seconds
(normal functioning):
- Fuel supply pressure shown by the pressure gauge [3] = 1.8 ± 0.4 bar.
- Fuel return pressure shown by the pressure gauge [3] = 0.5 ± 0.4 bar.
B1BP1TWD
Engines: RHY - RHZ
XSARA PICASSO
Angl.-t2-page283-305-2005 9/01/06 10:18 Page 288

Downloaded from www.Manualslib.com manuals search engine 289
INJECTION
CHECKS: LOW PRESSURE FUEL SUPPLY CIRCUIT
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 3and 3.5bar0.7 ± 0.2 bar Check the condition of the diesel filter
More than 3.5bar Less than 0.7barCheck the low pressure regulator incorporated
in the filter
(locked shut): replace.
More than 3.5bar More than 0.7barCheck the fuel return circuit
(pipe pinched or trapped…)
Between 0.8and 1.5bar Less than 0.7barCheck the fuel supply circuit:
- Booster pump (low pressure), piping
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: Observe:
The flow should be drop by drop Diesel injector functioning correctly
Excessive fuel return Diesel injector locked shutEngines: RHY - RHZ (continued)
XSARA PICASSO
Angl.-t2-page283-305-2005 9/01/06 10:18 Page 289