Service of the Infiniti QX4 since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
5. Cooling system and heating
6. Feed and control systems
6.1. Specifications
6.2. System of the consecutive distributed injection (SFI)
6.3. Dropping pressure in a power supply system of petrol engines
6.4. Check of a state and replacement of fuel lines and their nipple connections
6.5. Systems of electronic control - the general information
6.6. Control system of the VG33E engine. Procedures of diagnostics
7. Systems of start and charge
8. Transmission line
9. Brake system
10. Suspension bracket and steering
11. Body
12. Electric equipment


6.2. System of the consecutive distributed injection (SFI)

The scheme of an arrangement of components of a control system of consecutive injection (SFI) in a motive compartment

In systems of consecutive injection each of 6 (by the number of cylinders) fuel injectors works at the time of the beginning of opening of the corresponding inlet valve. Thus, fuel is injected into cylinders according to order of operation of spark plugs.

During start of the engine and in case of failures of the system of management (emergency operation) the system passes into the mode of simultaneous injection of fuel in all cylinders of the engine.

The main components of the SFI system are:

  • The catalytic converter of the closed type, systems of catching of fuel evaporations (EVAP) and recirculation of the fulfilled gases (EGR).

By efficiency of functioning the system answers all with requirements of the international standards. The description of the principle of functioning of the part of system which is responsible for fuel injection the engine is given below. Information on functioning of a subsystem of ignition — see the Control system of the VG33E engine. Procedures of diagnostics.

The submersible fuel pump placed in the fuel tank provides supply of fuel under pressure to the fuel highway, on the way banishing it through the fuel filter installed behind under the car. The pressure of supply of fuel is defined by pressure regulator installed on the throttle case. Excess of fuel on the returnable line goes back to the fuel tank.

Electric part of a control system consists of the electronic module of management (ECM) and the following information sensors (see the illustration Scheme of an Arrangement of Components of a Control System of Consecutive Injection (SFI) in a motive compartment):

  • The sensor of situation (potentiometer) of a butterfly valve (TPS) informs ECM on the provision of a butterfly valve;
  • The sensor of temperature of cooling liquid (ECT) informs ECM on temperature of cooling liquid of the engine;
  • The sensor of temperature of the soaked-up air (IAT) informs ECM on temperature of the air which is soaked up in the inlet pipeline;
  • The lambda probe (models for Great Britain) informs ECM on concentration of content in the fulfilled gases of the molecules O 2;
  • The sensor of provision of a bent shaft (CKP) informs ECM on turns of the engine and the provision of a bent shaft;
  • The sensor of position of the camshaft (CMP) informs ECM on situation and frequency of rotation of the final camshaft;
  • The sensor of a detonation (KS) informs ECM on emergence of signs of early ignition;
  • The sensor of measurement of mass of air (MAF) informs ECM on amount of the air coming to the inlet pipeline;
  • The sensor of absolute pressure in the inlet pipeline (MAP) informs ECM on load of the engine, tracing depression depth in the inlet pipeline;
  • The control unit of system of anti-blocking of brakes (ABS) informs ECM on the speed of the movement of the car;
  • The sensor switch of the air conditioning system (at the corresponding complete set) notifies ECM on the fact of turning on of the conditioner.

All arriving information is processed by ECM which then issues commands of management of ignition and opening of an injector of injection of fuel. Management of an injector happens by change of width of the operating electric opening impulse that allows to make with the minimum delay correction of composition of air-fuel mix at change of external factors. Thanks to a possibility of such adjustments return of the engine is supported at the maximum level at any stage of functioning of the unit: at start, during warming up, at acceleration, a deseleration and the movement with a constant speed.

ECM exercises also control of idling turns. Necessary adjustments are made by activation of the throttle of the step electric motor established on the case. The engine on the ECM teams makes a bypass opening / overshoot, in case of need (for example, at the butterfly valve closed or being in the provision of idling) starting up air bypassing the throttle camera.

Besides, ECM exercises control of functioning of system of catching of fuel evaporations of EVAP.

If from sensors information confirming emergence not of an emergency situation arrives, ECM switches in emergency functioning when instead of inadequate signals basic values of the corresponding parameters are substituted — efficiency of return of the engine in such mode, naturally, decreases. Prevents operation of a control lamp of refusals on an instrument guard of the car about ECM entrance to emergency operation of the driver (see the Head the Maintenance instruction), in the processor memory at the same time the corresponding diagnostic code is brought (see the Control system of the VG33E engine. Procedures of diagnostics).

At operation of a control lamp the car follows at the first opportunity to drive away on company car repair shop Opel for performing detailed diagnostics with use of the special equipment and performance of necessary recovery repair.

The diagnostic equipment (the reader of skanerny type) is connected to the DLC socket located under a decorative slip under ahead lever of the parking brake.

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6.1. Specifications
on the following page"
6.3. Dropping pressure in a power supply system of petrol engines