Fuel system - Service procedures
Injectors, replacement Special tool:6643, 981 2546 1 Drain the coolant. 2 Clean around the injectors, and at the pressure pipe and fuel return pipe connections. 7 3 Remove all pressure pipes. Remove the fuel return pipe at the injectors. Fit protection caps.
Fit the new injector together with the protection ring. Fit the yoke. Tightening torque 50 Nm (37 psi). 8
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Fit the pressure pipes and fuel return pipe.
Unscrew the injectors’ yoke. 9 5 Turn the injector with a wrench and pull upwards at the same time. If the injector is stuck, use extractor 6643.
Fill engine with coolant. Start the engine and check tightness at all connections. 10 Recheck water level.
Recommendations for adjusting opening pressure, setting pressure and changing injectors
6 Clean the bottom of the copper sleeve with tool 9812546 and a drilling-machine.
100
The injection process is carried out under very high pressure so that the dispersal of fuel is as effective as possible. As the injectors become older, opening pressure drops below the given pressure of new injectors. This pressure drop is completely normal and does not affect the function of the injectors or the engine performance to any great degree. Adjusting the injectors can mean that the service life of the nozzle assembly is shortened.
