Jeep Grand Cherokee

1993-1999 of release

Repair and car operation

System of injection of fuel - the general information

The system of multipoint injection of fuel (MPFI) consists of three subsystems: supply of air, electronic control and supply of fuel. The system in the work uses the module of management of RSM complete with various sensors (the sensor of temperature of a cooler, the sensor of provision of a butterfly valve (TPS), the sensor of absolute pressure in the pipeline (MAR), the oxygen sensor, etc.), on the basis of transferred by which information the module determines demanded current structure of an air and fuel mix (for specific conditions of functioning of systems of the car).

Arrangement of components of system of injection of fuel of the engine in volume of 4.0 l

Arrangement of components of system of injection of fuel of the engine in volume of 5.2 l.

The system of injection of fuel and the monitoring system of toxicity of the fulfilled gases and engine management are closely connected among themselves in work and on configuration. Additional information see in the Head of System of decrease in toxicity of the fulfilled gases and engine management.

System of giving (fence) of air

The system consists of an air purifier, sleeves of a fence of air, the case of a throttle, a control system of turns of idling and the inlet pipeline.

The sensor of provision of a butterfly valve (TPS) is fixed on an axis of a zaslonka and hands over information on the current provision of a zaslonka. On the models equipped with engines in volume of 5.2 l the sensor of absolute pressure in the pipeline (MAR) it is established in the throttle case whereas on models with engines in volume of 4.0 l it is fixed on a partition of an impellent compartment.

When the engine works at single turns, the structure of an air and fuel mix is supervised by system of stabilization of turns of idling (IAC) which consists of the module of management of RSM and the valve of additional air (IAC). The IAC valve turns on the module (RSM) depending on specific conditions of functioning of the engine (functioning of the conditioner of air, system of hydrostrengthening of a wheel, engine temperature, etc. conditions). The valve provides adjustment of an air stream behind a butterfly valve and in the inlet pipeline. RSM receives information from various sensors (the sensor of speed of the car (VSS), the sensor of temperature of a cooler, sensors of modes of turning on of the conditioner of air and system of hydrostrengthening of a wheel, etc.) and makes adjustment of turns of idling according to requests of the engine and the driver.

Electronic control system

See. The head of System of decrease in toxicity of the fulfilled gases and engine management.

System of supply of fuel

The system consists of the following components: fuel pump, regulator of pressure of fuel, fuel injectors, resistor of an injector and main relays.

The fuel pump is established linearly and is the pump of a direct drive. Fuel is soaked up via the filter in the pump, passes the anchor line through the unilateral valve, arrives in the second filter and then moves in injectors. The safety valve serves for prevention of excessive increase of pressure and opens in case of blocking from the digit party, providing free pass of fuel from a high-pressure head part of system in the low-pressure head.

The regulator of pressure serves for maintenance of pressure of fuel on injectors the constant set level. Excess of fuel arrives back in a fuel tank on the returnable line.

Injectors - plunzherny type with a constant course operate from electromagnets. Injectors consist of an electromagnet, a plunzher, the needle valve and the case. When giving current on the electromagnet solenoid the needle of the valve rises and fuel under pressure arrives in the injector case, and then through a nozzle is injected into the engine. The amount of injected fuel is defined by extent of clock pulse of opening of the valve (width of an impulse of an electromagnet of a current submitted on the solenoid).

In a type of that it defines intervals of opening and closing of injectors that, in turn, defines structure of an air and fuel mix, distribution of the moments of operation of injectors should be exposed very precisely. For ensuring the most effective operation of injectors the front of impulses of a current when giving tension on the solenoid of each of injectors should be as it is possible more abruptly. Thus, the quantity of windings of the solenoid is minimized for the purpose of decrease in inductance. However, it conducts to decrease in resistance of the solenoid that reduces injector service life. The size of a current is limited to the resistor established in a plait of wires of an injector.

The main relay which is established near the assembly block of safety locks, is the relay of direct inclusion, and contains the relay of a food of the electronic control unit and the relay of giving of a food on the fuel pump.