General information
The fuel system consists of a gas tank. located behind the car body, an electric fuel pump. immersed in the gas tank, fuel filter. Fuel supply and return pipelines. The fuel pump delivers fuel to the fuel rail, which acts as a common reservoir for four injectors that inject fuel into the intake tracts of the cylinders. Before entering the rail, the fuel passes through a filter.
On M43TU and M52TU engines, the fuel pressure regulator is mounted on the fuel rail. On N42 and M54 engines, the fuel pressure regulator is built into the fuel filter (pic. 1.1). The fuel injection system is described in more detail in paragraph 7 and the exhaust system in paragraph 14.
Pic. 1.1. Fuel system
A M43TU and M52TU engines
In N42 and M54 engines
1 fuel tank
2 Electric pump
3 Calming chamber
4 Pressure limiting valve
5 Safety valve
6 Extraction pump
7 Tank expansion tube
8 Shut-off valve
9 Filler neck
10 Filler cap
11 Ventilation hose
12 Pressure pipeline
13 Fuel return line
14 Ventilation hose
15 Ventilation hose
17 Expansion tank
18 Rollover valve
20 Fuel filter
21 Fuel pressure regulator
23 Fuel rail with injectors
24 BZU
25 intake manifold
26 Tank vent valve
27 Purge line
28 Ventilation pipe
30 Evaporation pipe
31 Carbon absorber
Cautions
Attention! Many of the operations described in this chapter involve disconnecting fuel lines, which may result in some fuel being spilled. Before starting work, carefully read the warnings in section "Safety first!" at the beginning of this book and strictly follow them. Gasoline is a volatile and very dangerous liquid, so no precautions will be superfluous when working with it.
Attention! Excessive pressure continues to remain in the fuel system long after the engine has stopped. Therefore, before disconnecting any fuel line, depressurize the system as described in paragraph 8.