S-class W202 Mercedes

1993-2000 of release

Repair and car operation

W202 Mercedes
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
+ 7. Ignition system
- 8. Fuel system
   - 8.1.1. Introduction
      8.1.2. Fuel tank
      8.1.3. Fuel level sensor
      8.1.4. Fuel pump
      8.1.5. Fuel filter
      8.1.6. Air filter
      8.1.7. Cross-section pipe of the air filter
      8.1.8. Inlet gas pipeline
      8.1.9. Cable gas / lever of a butterfly valve (DB)
      8.1.10. Cable of management of gas (DB)
      8.1.11. Contour of fuel of the diesel engine
      8.1.12. Prestarting heating of diesel fuel
      8.1.13. Fuel thermostat
      8.1.14. Hydrovalve case
      8.1.15. Cable gas / lever of a butterfly valve (DD)
      8.1.16. Cable of management of gas (DD)
   + 8.2. System of injection of petrol engines
   + 8.3. System of injection and food of diesel engines
   + 8.4. System of production of exhaust gases
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electroschemes

b47c026d b47c026d

8.1.12. Prestarting heating of diesel fuel


To guarantee normal fluidity of diesel fuel and thanks to it to prevent obstruction топливопроводов and filters, in particular at big colds, fuel is warmed up previously according to ambient temperature.

Toplivopodkachivayushchy the pump sucks in fuel from a tank via the fuel filter of rough cleaning. Thus diesel fuel directly proceeds in front of the toplivopodkachivayushchy pump of the fuel thermostat which depending on temperature of fuel defines degree of prestarting heating of fuel.

Engine in volume of 2,0 l

Engine in volume of 2,0 l (party of low pressure)

1. Pump of nozzles
3. Fuel pump
15. Perepuskna valve
30. Nozzles
43. Filter of rough purification of fuel
50. Hose oil plum
63. Fuel tank
73А. Drosseliruyushchey an opening in the top part of the fuel filter
86. Fuel thermostat. The thermostat is closed, fuel is not warmed up.
89. The device with the central fastening
148. Fuel heat exchanger
A–An admission from a tank
B–The pipeline to the fuel pump
C–The submitting line to the heat exchanger
D–Inflow from the heat exchanger
E–A supply of cooling liquid
F–The party of an obeganiye of cooling liquid

For prestarting heating diesel fuel arrives from the thermostat through the line submitting diesel fuel (C) to the heat exchanger (148) to the fuel submitting line (Е), through a drain of diesel fuel (D) again back in the thermostat and from there by means of the fuel pump in the fuel filter.

If the temperature of fuel is lower 18 ° than C, the thermostat is completely open and all amount of fuel flows via the heat exchanger. At temperature from 18 to 30 ° C the mixed mode prevails, i.e. fuel partially flows via the heat exchanger and is partially direct to the toplivopodayushchy pump. At temperature above 30 ° the C supply of fuel to the heat exchanger from the thermostat stops.

The thermostat is established outside on the heat exchanger. And – supply of fuel from a fuel tank, In – the inlet pipeline to the fuel pump, Е – an input of cooling liquid, F – an exit of cooling liquid.

Engines in volume of 2,2/2,5 l

Fuel flows in front of the fuel filter via the heat exchanger which is screwed in sideways in a cylinder head. In the heat exchanger the thermoelement which depending on temperature of fuel directs its stream in whole or in part via the heat exchanger is above got: from 18 ° C to 30 ° the C mixed mode, over a temperature 30 ° C – without prestarting heating.