6.2.1. Principle of functioning of systems of injection of fuel

System of the central injection MulTec

The components which are a part of the MulTec system are listed on an accompanying illustration. By efficiency of functioning the system answers all with requirements of the international standards.

Main components and function chart of system of injection of MulTec (OHC engine of 1.2 l)

1 — the Injector
2 — the fuel pressure Regulator
3 — Step э / the motor of system of stabilization of turns of idling
4 — the Sensor of temperature of the soaked-up air (IAT)
5 — the Potentiometer of a butterfly valve (TPS)
6 — pressure Sensor in inlet the pipeline (MAP)
7 — the Fuel filter
8 — the Fuel pump
9 — the Relay of the fuel pump
10 — the Frequency sensor of a run
11 — the Control lamp of refusals (MIL)
12 — DIS ignition Module
13 — the Catalytic converter
14 — the Rechargeable battery

15 — the ignition Lock
16 — the Diagnostic socket
17 — the Lambda probe
18 — the Adsorber of vapors of fuel of the EVAP system
19 — the EGR Valve
20 — the Control valve of the EVAP system
21 — the Sensor of a detonation (KS)
22 — the EGR Control unit
23 — the adjustment Block on a detonation
24 — the CKP Sensor
25 — the Cogwheel of a bent shaft with a CKP sensor rotor
26 — the throttle Case
27 — the Control unit of the engine (ECM)
28 — the Fuel tank

The fuel pump gives fuel from a tank via the fuel filter to the case of a throttle or to the fuel distributive highway.

Air-fuel mix is injected into the throttle case by means of the central injector and comes to the inlet pipeline from where it is distributed on separate cylinders. The regulator of pressure supports pressure in the inlet pipeline at the level of 0.76 atm.


4 injectors are attached to the fuel highway. The regulator of pressure supports in the highway pressure of fuel, equal 3.0 atm. Injectors are run by electronics and inject fuel at the same time into the inlet pipeline in front of inlet valves.

Air is sucked in by the engine via the air filter and a branch pipe of a butterfly valve by means of which the necessary amount of fuel is regulated. Depression in the inlet pipeline is registered the corresponding sensor, also as well as temperature of the soaked-up air. The module of management determines the mass of the soaked-up air by these parameters. The sensor of pressure of the soaked-up air is on a partition of a motive compartment and is connected through a vacuum hose with the inlet pipeline.

ECM according to the mass of the soaked-up air and other parameters, such as, engine temperature, regulates the required amount of injectable fuel.


From the fuel distributive highway fuel arrives to injectors. Pressure regulator in the highway watches that pressure in it was supported equal 3.0 atm. Management of injectors is made separately. The injection is made according to the sequence of ignition, at the necessary moment.

On the engine of 1.6 l 109 h.p. the mass of the soaked-up air is registered the MAF sensor. On other engines the mass of the soaked-up air is determined by depression size in the inlet pipeline. Definition on weight is made more precisely and quicker. ECM according to the measured mass of air and other parameters, such as engine temperature, regulates amount of injectable fuel.

System of injection Bosch Motronic 1.5.5

On accompanying illustrations components of system of injection of DOHC 1.0 and 1.2 engines of l are presented.

Components of system of injection Bosch Motronic (l DOHC 1.0 and 1.2 Engines)

1 — the MAF Sensor
With definition of the return stream, i.e. when calculating amount of injectable fuel the volume of the air rejected when closing inlet valves is considered. It provides more exact supply of fuel.
In addition the sensor of temperature of the soaked-up air is integrated into the case of the measuring instrument of mass of air
2 — TPS
Transfers ECM information on the current provision of a butterfly valve.

3 — Step э / the motor of a butterfly valve
On the basis of ECM signals step э / the motor establishes the provision of a butterfly valve and by that idling speed
4 — the ignition Module
The module of ignition is put on spark plugs and fixed to a cover of a head of cylinders. For each spark plug there is the coil of ignition which is located directly over the built-in socket of a spark plug. VV a wire is absent
5 — the Lambda probe
6 — the CMP Sensor

Components of system of injection Bosch Motronic (l DOHC 1.0 and 1.2 Engines)

1 — the detonation Sensor
2 — the Valve of management of an EVAP system adsorber purge
3 — the CKP Sensor
4 — the Monitor the engine
It is located directly at the engine or at the inlet pipeline. It provides the minimum length of a cable. Has 2 sockets: for the engine and a combination of devices

5 — the EGR system Valve
It is located in the EGR case and ECM copes and regulates amount of the fulfilled gases returned in the engine. The EGR case is fixed on a head of cylinders and connects a final collector via the channel going in a head of cylinders with the inlet pipeline. In the EGR case the channel of cooling liquid going to a heater is located.
Near the EGR valve there is an ECT sensor giving a signal on the index located on a combination of devices
6 — the ECT Sensor
Transfers data on OZh temperature for ECM

Elements of system of injection (all engines)

TPS is located directly on an axis of a butterfly valve. He transfers to ECM information on the current provision of a butterfly valve.

The relay of the fuel pump is located in a foot well, behind a cover of the right rack of A. In the same place there is ECM. The relay operates giving of food on the fuel pump and interrupts food as soon as receipt of impulses of ignition stops, for example, if the engine becomes deaf.

The CKP sensor is sideways in a motive compartment. He transfers information on the speed of the bent shaft ECM.

The lambda probe measures concentration of oxygen in a stream of the fulfilled gases and transmits the corresponding signals of ECM. On the basis of the obtained information of ECM changes quality of air-fuel mix that provides optimum reburning of the fulfilled gases in the catalytic converter.

Step э / the motor of system of stabilization of idling regulates idling speed, supporting him invariable, irrespective of use of additional units, such as GUR or K/V. Control of the electric motor is exercised by ICM.

The control valve of the EVAP system is on a partition of a motive compartment. At the open valve of couple of fuel from an adsorber move on absorption and are burned in the engine.

In an adsorber accumulation of vapors of fuel which are formed in the fuel tank owing to change of temperature is made. The collected fuel evaporations then are used and do not get to the atmosphere.

Existence of regulation of a detonation provides on the engine 1.2 l and l DOHC 1.4 and 1.6 engines a possibility of work on border of a detonation and adaptation to quality of the applied fuel. Regulation of a detonation allows the engine to work with high extent of compression. It in turn provides a possibility of optimum use of energy of fuel that leads to decrease in its expense.

The MAF sensor on engines of 1.6 l (109 h.p.) is at the exit of the air filter. In the case of the MAF sensor there is a thin heated film which is cooled with a stream of the air which is flowing round it. The control system regulates heating current so that the film temperature (controlled on resistance) remained a constant. If, for example, as a result of increase in an angle of opening of a butterfly valve the bigger amount of air is sucked in, the plate is cooled. As a result value of current of heating that temperature remained a constant increases. Value of current at the same time corresponds to the mass of the sucked-in air.

The CKP sensor serves in the MULTEC-S system for definition of the cylinder for consecutive injection. Thanks to this ECM sensor defines, for example, when the piston of the cylinder 1 is in VMT.

On l DOHC 1.4 and 1.6 engines from 09.1994 g of release the system of admixture of additional air corrects composition of the fulfilled gases at warming up of the engine.