DAF CF65, CF75, CF85 Series . Manual - part 416

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General

CE ENGINE FUEL SYSTEM

ΧΦ65/75/85 series

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2

Location of components, production date 
 2003-49 (chassis number  0E628656) 

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CE ENGINE FUEL SYSTEM

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General

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ΧΦ65/75/85 series

4

1.

Suction pipe to electronic unit cooling plate

2.

Fuel rail pressure sensor

3.

Fuel pipe to fuel rail

4.

Fuel rail

5.

Fuel return overflow valve

6.

Fuel rail pressure-limiting valve

7.

Return pipe from fuel return overflow valve 

8.

Fuel pipe to fuel fine filter

9.

High-pressure pump leak-off pipe

10. Fuel pipe to fuel lift pump
11. High-pressure pump
12. Return pipe to fuel tank
13. Fuel pump control solenoid valve
14. Fuel pipe to high-pressure pump
15. Fuel supply pipe
16. Fuel fine filter
17. Fuel pipe from electronic unit cooling plate
18. ECS-DC3 electronic unit

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 200416

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General

CE ENGINE FUEL SYSTEM

ΧΦ65/75/85 series

4

2

2.2 SYSTEM DESCRIPTION, ECS-DC3 FUEL SYSTEM

The fuel lift pump (4a) draws the fuel from the fuel 
tank (1) through the cooling plate of the electronic 
unit (3).
The purpose of the cooling plate (3) is to ensure 
that the electronic unit does not become too hot.
The fuel lift pump (4a) is fitted against the high-
pressure pump (4c) and is driven by the camshaft 
gear.
From the fuel lift pump, fuel is forced towards the 
fuel fine filter (5).

After the filter, the fuel enters the high-pressure 
pump (4c) via the fuel pump control solenoid 
valve (4b), which controls the amount of fuel 
going to the high-pressure pump. Fuel not taken 
in by the high-pressure pump returns via the by-
pass valve (4d) to the fuel lift pump supply pipe 
and part of it is used for lubricating the high-
pressure pump.

The high-pressure pump forces the fuel under 
high pressure to the fuel rail (6). The fuel rail 
distributes the fuel among the injectors (7). The 
fuel rail (6) also functions as an accumulator to 
ensure that large fluctuations in pressure, 
resulting from injector openings and pump 
pressure pulses, are prevented as much as 
possible.

The pressure in the fuel rail is registered by the 
rail pressure sensor (6a). The electronic unit uses 
this data to control the high-pressure pump (via 
the fuel pump control solenoid valve), so that the 
rail pressure can be kept at the desired level. The 
desired pressure is not constant, but depends on 
the operating conditions.

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CE ENGINE FUEL SYSTEM

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General

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ΧΦ65/75/85 series

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A pressure relief valve (6b) is fitted at the end of 
the fuel rail. If the pressure in the fuel rail rises too 
high (in emergencies only), this valve ensures 
that the excess fuel flows back to the return pipe. 
The return pipe is connected with the return pipe 
to the fuel tank (1).

The electronic unit uses the present rail pressure 
to calculate the time during which the injector 
needs to be opened in order to obtain the desired 
injection quantity.

A pressure relief valve (8) connects the injector 
leak-off ducts in the cylinder head with the return 
pipe to the fuel tank (1). This pressure relief valve 
prevents the fuel from flowing out of the injectors 
when the engine has stopped running.

If the system has been "open", the fuel system 
can be bled using the primer pump (2a), which 
is integrated in the water separator/coarse 
filter (2b).