Siemens-Fenix 3 central injection system
Models 1.4 l (E7J engines) Equipped with Siemens-Fenix 3 central fuel injection system with Bosch throttle body. The system includes a catalytic converter and a fuel vapor recovery system.
The fuel priming pump delivers fuel from the tank to the injectors, through a filter installed at the rear of the car. The fuel supply pressure is controlled by a pressure regulator that is installed in the throttle body assembly.
The electrical control system consists of an electronic control unit (ECU), along with the following sensors:
- a) Throttle Potentiometer - provides the electronic control module with information about the position of the throttle valve and the degree of its opening.
- b) Coolant temperature sensor - provides the electronic control module with information about the temperature of the engine.
- With) Inlet air temperature sensor - provides the electronic control module with information about the temperature of the air passing through the throttle body.
- d) Lambda sensor - provides the electronic control module with information about the oxygen content in the exhaust gases.
- e) microswitch (included in the idle speed control stepper motor) - provides the electronic control module with information about the closing of the throttle valve (i.e. when the gas pedal is released).
- f) Speed/Crankshaft Position Sensor - Provides information to the electronic control module about engine speed and crankshaft position.
- g) Power steering pressure sensor - provides the electronic control module with information about the use of the power steering pump, the module increases the idle speed.
- h) Knock sensor - provides the electronic control module with information about the engine load by monitoring the pressure in the intake manifold.
- f) Vapor recirculation valve - controlled by the fuel vapor recirculation system.
All of the above information is analyzed by the ECU, which then corrects the ignition timing and fuel delivery to the engine. The ECU controls the operation of the injectors by changing the duration of the injection (the period during which the injector is open), to enrich or lean the mixture as needed. The ECU constantly adjusts the ratio of the mixture, ensuring the best engine performance in various modes.
The ECU also regulates the idle speed via a stepper motor mounted in the throttle body. The motor pusher rests against a cam on the throttle axis. When the throttle is closed (gas pedal not pressed), the ECU uses the motor to change the throttle position and thus adjust the idle speed.
The ECU also controls the EGR and EVAP systems.
If one of the sensors fails, the ECU activates the source memory block containing the regulated values of all factors. In this case, the ECU ignores the incorrect sensor signal and replaces it with the value taken from the memory unit. If the ECU accesses the original memory block, a warning lamp on the instrument panel lights up and the corresponding DTC is stored in the ECU memory.
If the control lamp lights up, contact a Renault workshop as soon as possible, which will perform a complete diagnosis of the engine management system using a special electronic tester (XR25), which is simply plugged into the diagnostic connector (mounted on the fuse box on the dashboard).
The fuel cut switch is built into the fuel injection system. In the event of an accident, the switch cuts off the power supply to the fuel pump, thus preventing fuel from spilling when the fuel lines break.
Siemens-Fenix 5 semi-sequential port injection system
K7M engines are equipped with a semi-sequential distributed fuel injection system with a Pierburg throttle body. This system is basically the same as the center injection system described in the previous paragraphs, except that there are four injectors in the intake manifold (one per cylinder). All injectors are fed from a common fuel line equipped with a fuel pressure regulator.
In a semi-sequential injection system, the injectors work in pairs (1 and 4 and then 2 and 3). During one revolution of the engine, fuel is injected into each cylinder once, that is, during a complete 4-stroke cycle, fuel is injected into the cylinders twice.
The system has an exhaust gas recirculation valve.
On automatic transmission models, information from sensors on the transmission is sent to the electronic control module for processing to determine the most efficient parameters for the engine.
Siemens-Fenix 5 sequential multiport injection system
The F3R and F7R engines are equipped with a sequential multiport injection system with a Solex throttle body (F3R) or Magneti Marelli (F7R). This system is most similar to the central injection system described earlier, except that it has four injectors (one per cylinder), installed directly in the intake manifold or in the cylinder head. All injectors are fed from a common fuel line, which also has a fuel pressure regulator.
In a sequential injection system, the injectors work individually. The combined signal from the camshaft position and speed/crankshaft position sensors is used by the ECM to determine engine speed, crankshaft position, and cylinder stage. And information about engine speed and piston position relative to TDC comes from the speed / crankshaft position sensor; information about. which of the two pistons is at TDC on the compression stroke comes from the camshaft position sensor. Based on this data, the electronic control module is able to determine the start of fuel injection for each cylinder separately. Other information from additional sensors allows the electronic control module to calculate the injector open time depending on temperature, engine speed and engine load.
On models with the F7R engine, an EGR valve is also included in the system.
On models with the F7R engine, dual-flow intake piping is used to provide the required intake air flow at low engine speeds to obtain sufficient torque, and at high engine speeds to obtain sufficient power. That is, there are two separate, parallel working, inlet air ducts controlled by a damper and an electromagnetic unit. Depending on the engine speed, one of the two air intake ducts will be opened or closed, providing the required airflow in all operating modes.