DAF 95XF. Manual - part 385

4

DIAGNOSIS

XE engine fuel system

95

XF series

5-4

FAULT: REDUCED POWER AT ALL SPEEDS

Possible cause

Remedy

Poor fuel quality.

Drain fuel, rinse the fuel system, replace the fuel
filters and fill the fuel tank with fuel.

Fuel fine filter/fuel coarse filter blocked.

Replace the fuel fine filter and clean the system.

Pompunits mechanisch defect of verstopt.

Replace the pump units.

Accelerator pedal sensor, mechanical defect.

Check:
-

mechanical connection sensor/accelerator
pedal

-

accelerator pedal sensor.

Mechanical defect or clogging of pump units.

Replace the pump units.

Injector defective.

Check the injectors.

Pressure-relief valve on pump housing does not
shut off.

Check gallery pressure.

Fuel lift pump output too low.

Check:
-

the fuel lift pump and replace, if necessary

-

gallery pressure.

Fault in electrical components/wiring of:
-

accelerator pedal sensor

-

sensor for engine coolant temperature

-

boost pressure sensor

-

fuel temperature sensor

-

connectors.

Check the electrical system.

FAULT: REDUCED POWER ABOVE A PARTICULAR SPEED

Possible cause

Remedy

Fuel fine filter/fuel coarse filter partially blocked.

Replace the fuel fine filter and clean the system.

Mechanical defect or clogging of pump units.

Replace the pump units.

Air leaks in inlet system.

Pressure-test the inlet system.

Pressure-relief valve on pump housing does not
shut off.

Check gallery pressure.

Fuel lift pump output too low.

Check:
-

the fuel lift pump and replace, if necessary

-

gallery pressure.

Fault in electrical components/wiring of:
-

electro-pneumatic boost pressure valve

-

connectors.

Check the electrical system.

1

©

 0008

4

95

XF series

XE engine fuel system

DIAGNOSIS

5-5

FAULT: WHITE/BLUE SMOKE DEVELOPMENT

Possible cause

Remedy

Slechte brandstofkwaliteit.

Drain fuel, rinse the fuel system, replace the fuel
filters and fill the fuel tank with fuel.

Air in the fuel system.

Check the fuel system for drawing in air:
-

through suction pipe

-

through sealing ring of fuel lift pump.

Fuel fine filter/fuel coarse filter blocked.

Replace the fuel fine filter and clean the system.

Mechanical defect or clogging of pump units.

Replace the pump units.

Injector defective.

Check the injectors.

Fuel lift pump output too low.

Check:
-

the fuel lift pump and replace, if necessary

-

gallery pressure.

Fault in electrical components/wiring of:
-

crankshaft position sensor

-

sensor for engine coolant temperature

-

connectors.

Check the electrical system.

FAULT: BLACK SMOKE DEVELOPMENT

Possible cause

Remedy

Injector defective.

Check the injectors.

Fault in electrical components/wiring of:
-

crankshaft position sensor

-

air inlet temperature sensor

-

fuel temperature sensor

-

boost pressure sensor.

Check the electrical system.

FAULT: ENGINE OVERHEATED

Possible cause

Remedy

Poor fuel quality.

Drain fuel, rinse the fuel system, replace the fuel
filters and fill the fuel tank with fuel.

Fault in electrical components/wiring of:
-

sensor for engine coolant temperature.

Check the electrical system.

1

©

 0008

4

DIAGNOSIS

XE engine fuel system

95

XF series

5-6

FAULT: FUEL CONSUMPTION TOO HIGH

Possible cause

Remedy

Poor fuel quality.

Drain fuel, rinse the fuel system, replace the fuel
filters and fill the fuel tank with fuel.

Fuel fine filter/fuel coarse filter blocked.

Replace the fuel fine filter and clean the system.

Mechanical defect or clogging of pump units.

Replace the pump units.

Injector defective.

Check the injectors.

Leaks in fuel system.

Check for leaks.

Fault in electrical components/wiring of:
-

sensor for engine coolant temperature

-

boost pressure sensor

-

fuel temperature sensor.

Check the electrical system.

FAULT: REDUCED MAXIMUM SPEED

Possible cause

Remedy

Air in the fuel system.

Check the fuel system for drawing in air:
-

through suction pipe

-

through sealing ring of fuel lift pump.

Fuel fine filter/fuel coarse filter blocked.

Replace the fuel filter and clean the system.

Mechanical defect or clogging of pump units.

Replace the pump units.

Fuel lift pump output too low.

Check:
-

the fuel lift pump and replace, if necessary

-

gallery pressure.

Fault in electrical components/wiring of:
-

crankshaft position sensor

-

accelerator pedal sensor

-

sensor for engine coolant temperature.

Check the electrical system.

1

©

 0008

4

95

XF series

XE engine inlet/exhaust system

DIAGNOSIS

6-1

6.  XE ENGINE INLET/EXHAUST SYSTEM

6.1

FAULT-FINDING TABLE

FAULT: REDUCED POWER AT ALL SPEEDS

Possible cause

Remedy

Air filter clogged.

Replace or clean the air filter.

Turbocharger defective/incorrect wastegate
control.

Check wastegate or wastegate control.

Electro-pneumatic boost pressure valve
defective.

Check electro-pneumatic boost pressure valve.

Air leaks in inlet system.

Pressure-test the inlet system.

FAULT: REDUCED POWER ABOVE A PARTICULAR SPEED

Possible cause

Remedy

Air filter partially clogged.

Replace or clean the air filter.

Electro-pneumatic boost pressure valve
defective.

Check electro-pneumatic boost pressure valve.

Air leaks in inlet system.

Pressure-test the inlet system.

FAULT: FUEL CONSUMPTION TOO HIGH

Possible cause

Remedy

Turbocharger defective.

Check the turbocharger.

Air leaks in inlet system.

Pressure-test the inlet system.

FAULT: REDUCED MAXIMUM SPEED

Possible cause

Remedy

Turbocharger defective.

Check the turbocharger.

©

 0008

1