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
   - 8.2. System of injection of petrol engines Principle of work of PMS Principle of work of HFM
      8.2.2. Self-diagnosing of a condition of system of ignition and fuel injection
      8.2.3. Air flowmeter
      8.2.4. A temperature-sensitive element of cooling liquid
      8.2.5. The sensor of soaked-up air
      8.2.6. System of vacuum pipelines
      8.2.7. The fuel distributor with klapanny nozzles
      8.2.8. Klapannye of a nozzle
      8.2.9. Oxygen sensor (lambda probe)
      8.2.10. Diagnostics of malfunctions of system of injection of gasoline
      8.2.11. That it is necessary to know to the owner of the car with the injector engine
      8.2.12. Turbo doctor
   + 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 Principle of work of PMS


Engines in volume of 1,8/2,0 l

PMS scheme – systems of injection of fuel (engines in volume of 1,8/2,0 l)

36. The thermostat (only at type 124)
40. Membrane regulator of pressure
41. A membrane quencher of pressure (only at type 124)
55. Fuel filter
60. System of modulating pressure of the membrane mechanism of a vacuum regulator of an advancing of ignition (only in the presence of an automatic box peredy)
75. Fuel tank
77. A tank with absorbent carbon
82. The pipeline under depression
156. Inlet gas pipeline
158. Catalyst
159. Final collector
А1р5. Indication of temperature of cooling liquid
B11/3. A temperature-sensitive element of cooling liquid
В17. A temperature-sensitive element of soaked-up air
G3/2. Oxygen sensor
K3/1. System of partsialny heating of the inlet gas pipeline (only at type 124)
К27. Relay of the fuel pump
L5. Item sensor of a cranked shaft
M3. Fuel pump
M16/6. Executive body of system of regulation of frequency of rotation of a shaft of the engine when idling
N3/6. Control unit engine (PMS)
N6. Control unit conditioner
N30. ABS control unit
R16/7. The leveling shtekkerny socket
R33. WITH - a potentiometer, only at cars without the catalyst (abroad)
S2/1. Ignition and starter switch
S16/1. Switch of blocking of inclusion of a starter and switch of headlights of a backing
T1/1. The coil of ignition 1 for cylinders 1 and 4
T1/2. The coil of ignition 2 for cylinders 2 and 3
W14. A weight point on the holder of the hydraulic block of ABS system
X4/10. Connecting block
X11/14. The central tip for connection of the diagnostic stand
X12/3. The plug 30/15 of a connecting block without a safety lock
Y62. Klapannye of a nozzle


Instead of the thermostat (36) and the regeneration valve (51), type of engines 202 (S-class) is equipped with the switching valve which directly copes the PMS regulating device.

Fuel from a fuel tank is soaked up by the electric fuel pump and moves to klapanny nozzles via the fuel filter and the distributive pipeline. The pressure regulator on the distributive pipeline supports to constants pressure in fuel system depending on depression in an inlet pipe. Klapannye nozzles cope electric systems, and injection of fuel is carried out periodically, pushes in an inlet pipe in front of inlet valves. Thus klapanny nozzles cope poluposledovatelno, i.e. on each turn of a cranked shaft at the same time alternately injects respectively two klapanny nozzles. At malfunctions in ignition system for protection of the catalyst the relevant group is disconnected.

Air is sucked in by the engine via the air filter and the inlet gas pipeline. Depression in the inlet gas pipeline is registered a sensitive element and serves as criterion of quantity of the let-in quantity. As depression depends on the provision of a butterfly valve (the provision of a pedal of an accelerator), the amount of the let-in air is criterion of the actual loading of the engine. Therefore this control system is called as R-management where "R" is physical size of pressure.

The control system according to depression and this frequency of rotation of a shaft of the engine regulates injection time and by that amount of injected fuel. At rather long opening of a klapanny nozzle more fuel is injected. The additional sensor and executive links in extreme road situations care also of respectively measured amounts of fuel.

The actuation device of system of injection of fuel regulates frequency of rotation of a shaft of the engine in an idling mode by means of its zadatchik which regulates amount of air in an idling mode round a butterfly valve. Thanks to it constant frequency of rotation of a shaft of the engine in an idling mode irrespective of, whether direct additional consumers, such as the steering mechanism with the amplifier or the conditioner compressor are connected is reached.

1. Multicontact tip (lateral face of the car)
2. The multicontact tip (on the engine party)
83. The pipeline to the inlet gas pipeline, being under depression
R16/7. The leveling tip for fuel coordination
X12/3. The plug 15 of a connecting block without a safety lock

The control unit the engine (N3/6) is in a motor compartment on the left side.

Relay of the fuel pump (27) запитывает electricity fuel pump. The safety scheme interrupts current giving as soon as impulses of frequency of rotation do not arrive any more, for example, if the engine was stopped. The relay is located in a luggage carrier on the right side; 1–storage battery.

The oxygen sensor (lambda probe) measures the content of oxygen in a stream of exhaust gases and sends the corresponding signals of tension on the actuation device. After that the actuation device so regulates injected amount of fuel that fulfilled gases optimum дожигаются on the catalyst.

The temperature-sensitive element of let-in air takes its temperature, the second temperature-sensitive element on the case of a regulator of supply of cooling liquid changes temperature of the last.

The electromagnetic valve for aeration of a fuel tank copes depending on power setting. The allocated pairs of fuel are caught by the filter with absorbent carbon and via the valve move on combustion. Therefore, thanks to the filter filled with absorbent carbon, pairs of fuel mostly economically are used and do not get to the atmosphere.

On a flywheel (1) and on an inlet driving gear wheel of a camshaft inductive sensors (L5) are established. They hand over information on the actual frequency of rotation of a shaft of the engine and a position of a cranked shaft on the actuation device of system of injection of fuel.

The ignition system any more has no moving elements of a design and consequently up to spark plugs is not subject to wear. If in a motor compartment to disconnect to (pull together) leveling shtekkerny socket, it is possible to refuel fuel of more poor quality. If you again refuel gasoline for cars with the high-forced engines (the octane number 96–98, not less than 95 ROZ), again get leveling shtekkerny socket.