S-class W202 Mercedes
1993-2000 of release
Repair and car operation
+ 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
- 8.3. System of injection and food of diesel engines
8.3.2. Check / control of the beginning of supply of fuel by the pump
8.3.4. Specifications of system of injection and diesel engine food
8.3.5. Diagnostics of malfunctions of system of injection and food
+ 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
8.3. System of injection and food of diesel engines
The scheme of system of injection with a retsirkulyatsiya of exhaust gases
Engine in volume of 2,0 l: a food of nozzles provides the ryadny fuel pump of a high pressure of Bosch firm with a mechanical regulator and the built-in protivotolchkovy scheme of inclusion (KARA) which substantially reduces krutilny fluctuations in a driving phase.
Engine in volume of 2,2/2,5 l: the electronic system of regulation of a diesel engine (to EDC = electronic control of a diesel engine) promotes more exact coordination of injected amount of fuel with the corresponding operating mode of the car thanks to what, in comparison with mechanical systems, considerable improvements almost on all operating modes are reached.
Engine in volume of 2,2 l: the Mercedes firm places for the first time in operation adjustable electronic system of injection of fuel with use of the distributive fuel pump of a high pressure (EPIC = electronic programmed control of injection). Unlike the ryadny fuel pump of a high pressure which for each cylinder has a plunzherny pair, the distributive fuel pump of a high pressure is equipped only with two pistons of the pumping-up pump rotating in a rotor, and regulation of injected amount of fuel, and also peak distribution (distribution of the beginning of peak loading at increase of frequency of rotation in the direction of "early injection") is carried out by means of the piston hydraulically operated by means of electromagnetic valves.
Valves are started by the electronic actuation device. The type and duration of operating impulses depends on the factors registered by sensitive elements and processed in the actuation device by means of sorted universal characteristics. Frequency of rotation of the engine, and also temperature of the let-in air, cooling liquid and fuel concern them among the other pressure in the inlet gas pipeline.
Operation of the engine stops by means of the electromagnetic valve. If its power supply itself interrupts from the lock - the switch of ignition and devices of system of an anticreeper, or because of system mistakes in operating electronics, the valve blocks supply of fuel to pistons of the pumping-up pump. At malfunction of the disconnecting valve the actuation device establishes system of amount of injected fuel on "0" (zero giving) and, thanks to it, stops the engine. At the same time malfunction is remembered in the actuation device, and on the dashboard EDS - a control bulb flashes.
In addition with start of electromagnetic valves in the distributive pump of a retsirkulyatsiya of flue gases (AGR) in a combination to system of a drosselirovaniye of let-in air (ALD) it is regulated by means of the engine management valve, and AGR - the valve and a butterfly valve are respectively put in action from pneumatic zadatchik.
Engine in volume of 2,5 l: the 5-cylinder engine is also equipped with system of injection of fuel regulated by means of electronics in a combination to the ryadny fuel pump of a high pressure (M/RE).
Instead of a mechanical regulator of frequency of rotation (the engine in volume of 2,0 l) the electromagnetic executive mechanism assumes regulation by injected amount of fuel according to the provision of a pedal of an accelerator. Definition of provision of a pedal of an accelerator is carried out by means of a control unit by the engine, as well as at the engine in volume of 2,2 l.
Along with regulation of amount of injected fuel the electronic control unit power setting, besides, takes up regulation by a retsirkulyatsiya of flue gases (AGR) in a combination to a drosselirovaniye of let-in air (ALD) depending on frequency of rotation, loading and engine temperature.
Toplivopodayushchy the pump (13) is located outside of the ryadny fuel pump of nozzles. The filter of rough cleaning is in the case of the main filter, and warmed-up fuel thanks to what it, despite low external temperature, has the best fluidity from there follows.