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Fuel injection system (EFI) and engine management - models 4.2 l of release after 1992

general information

In an accompanying illustration shows the underside of the engine compartment model 4.2 l EFI with the location of various components of power systems and engine management.

Starting from October 1994, manufacturers refused to use a solenoid valve of the pressure regulator.

The engine management system in this manual called electronically controlled ignition of fuel (ECCS). The system manages both ignition and fuel injection.

ECCS is a central component of a control unit (ECU), representing a microprocessor. ECU operates the ignition timing and fuel injection amount based on the signals it receives from various sensors. At check-in load on the engine speed, vehicle speed, coolant temperature, throttle position, gear selection, intake air temperature and the composition of the exhaust gas ECU gives commands to the appropriate adjustment to the ignition timing and the time of opening fuel injectors in order to maximize the impact of the engine in the current environment.

When an abnormal signal register recurring ECU memorizes source circuit of the signal and stores it in the memory unit as a digital code, which greatly simplifies the procedure for fault diagnosis. If any fault angle sensor distributor or global internal fault within the ECU, affecting the efficiency of the engine is switched on control lamp "Check up the engine" on the instrument panel, together with which ECU includes a system of emergency operation that allows you to continue to operate a motor vehicle with a disabled engine to the cause of the failure. Read the faults from ECU memory in the workshop of dealer branch of the manufacturer of the vehicle facilitate diagnosis of the causes of failure.

The composition of the high-energy ignition system consists of the distributor, the powerful key of the output stage, the ignition coil and the connecting wiring.

The distributor has a dual function. Firstly, it is supplying the secondary coil voltage to the spark plugs. Second, the distributor delivers the ECU information about the engine speed and the position of the pistons. This information takes a rotation angle sensor disposed inside the distributor.
As for setting the ignition timing corresponds to the engine management system, the distributor is not equipped with either vacuum or centrifugal correctors ignition timing.

Powerful key output stage mounted near the ignition coil. And the function of interrupting the primary circuit, including at the team ECU. When this loop is induced in the secondary high voltage.

The ignition coil has a special design that meets the special requirements of the electronic ignition system and should only be replaced by a similar Statement.

Power engine provides multi-point electronic fuel injection. The system can inject fuel into the flow of intake air in the intake ports of the cylinder head. Next, the air-fuel mixture fed into the combustion chamber through the inlet valves.

The supply of fuel to the injectors provides a high-pressure pump submersible type mounted in the fuel tank. In order to suppress the fluctuation of fuel injectors and actuation due to their own functioning, the pump is equipped with a special damper.

The pressure in the feed system is maintained at 235 ÷ 294 kPa, depending on the pressure in the pipeline. Management by a special fuel pressure regulator mounted in the fuel line. When the engine is not running, the fuel injectors in the area between the gasoline pump and is pressurized by installing a one-way valve in the pump.

The amount of fuel injected is determined by the time of opening of injectors. The duration of the interval of opening of injectors ECU determined based on data obtained from the steering angle sensor and the meter distributor air flow. Basic injection duration can then be adjusted based on the information the coolant temperature sensor (CTS), sensors, switches the throttle and start authorization, the vehicle speed sensor, the position of the ignition key and data l-probe to obtain the engine maximum impact in concrete conditions and the current mode of operation.

Air controller provides increased engine idling speed in the process of warming up by bypass airflow to bypass the throttle. The operation of the air regulator controls the bimetal plate bends during heating electric shock. Arching, the bimetallic spring disc rotates in the air regulator, leading to a gradual reduction in the flow of air until it is completely overlap.

Block idle air control (IAA), mounted at the rear of the pump chamber of an air path, controls the engine idle speed. The unit is equipped with a screw rotation control, additional air valve and the device of indemnification of turns of fast idling (FICD).

AAS valve supplies additional air bypassing the throttle valve, thereby maintaining the idle speed at higher engine loads. The device acts like a valve FICD AAS, but is specifically for increasing the load compensation, due to the inclusion of the air conditioner.
Throttle body located on the plenum air path and controls the amount of air sucked into the engine depending on the accelerator position.

The efficiency of the engine management system depends on the accuracy of the information received on the ECU, the amount of controlled flow of air from the air flow meter. Therefore, special importance purity, quality and condition of the fixing of air, fuel and electrical connections.