What is meant by electronically controlled unit injection system?
An electronically controlled unit injector (EUI) is a unit injector (UI) with electronic control. It performs the same function as a conventional unit injector in an internal combustion engine, such as in an on-road or off-road vehicle or a diesel-electric locomotive.
How does a EUI injector work?
An electronic unit injector is a unit injector that has electronic control. Its camshaft-driven delivery of pressurized fuel coupled with management of the internal operations’ timing by an engine control unit allows electronic unit injectors to achieve certain benefits over conventional unit injectors.
What are the two main types of electronically controlled fuel injection system?
To understand the concept better, we first have to understand types of Fuel Injection. The Fuel Injection types used in newer cars are: Single-Point or Throttle Body Injection. Port or Multi-Point Fuel Injection.
What are the types of electronic fuel injection system?
The basic types of fuel injection systems are single-point fuel injection, multi-point fuel injection, sequential fuel injection, and direct injection.
What are the 3 main functions of the EUI fuel supply system?
The unit injection system integrates the injection pump and nozzle into a single module. This means the functions of fuel pressurization; injection timing, atomization and fuel distribution are accomplished using one single component.
What is a unit injector used for?
The unit injector system allows accurate injection timing, and amount control as in the common rail system . The unit injector is fitted into the engine cylinder head, where the fuel is supplied via integral ducts machined directly into the cylinder head.
What is the purpose of unit injector?
How does a TBI work?
TBI is a type of fuel injection system that has one or two fuel injectors mounted in a throttle body. The injectors deliver fuel into the air above the throttle plates. From there, the air-fuel mixture enters the intake manifold, where it is distributed to the engine’s individual cylinders.
What is a electronic unit?
An electronic control unit (ECU), also known as an electronic control module (ECM), is an embedded system in automotive electronics that controls one or more of the electrical systems or subsystems in a car or other motor vehicle.
What is the VOP for EUI fuel system?
The downward movement of the plunger pressurizes the fuel in the plunger cavity and nozzle. When the fuel pressure reaches the Valve Opening Pressure (VOP) of about 18.5 MPa (2,700 psi), the nozzle valve lifts off its seat and injection begins.
How does an electronic diesel pump work?
As the plunger moves back and forth, it leaves an opening for the fuel to go into the combustion chamber while moving backwards. While moving forwards, it creates enough force to compress the air in the chamber, which in turn creates enough heat to ignite the fuel and air mixture almost instantly.
How is electronic control used in a diesel injection system?
Most fuel injection systems use electronics to control the opening and closing of the nozzle. Electrical signals are converted into mechanical forces using some type of actuator. Commonly, these actuators can be either electromagnetic solenoids or active materials such a piezoelectric ceramics.
What is digital fuel injection?
Digital fuel injection refers to a fuel injection system that uses a digital signal from an onboard electronic control unit (ECU) to admit fuel into a carburetor style intake. While similar to that of throttle body injection, the system uses no sensors to help regulate the fuel flow.
What are two disadvantages to using electronic fuel injection?
Disadvantages of Electronic Fuel Injection System High maintenance cost. Difficulty in servicing. Possibility of malfunction of some sensors.
What’s the difference between TBI and EFI?
ALL fuel injection can be classified as Electronic Fuel Injection (EFI). TBI is an EFI setup that utilizes Throttle Body Injection (looks like a carburetor). The TBI units have two injectors that meter the fuel for all the clyinders at once (again, similiar to a carburetor).
What is an electronically controlled unit injector?
An electronically controlled unit injector ( EUI) is a unit injector (UI) with electronic control. It performs the same function as a conventional unit injector in an internal combustion engine, such as in an on-road or off-road vehicle or a diesel-electric locomotive.
Are mechanical injectors still used in engines?
Mechanical unit injectors-while having been largely replaced by electronic unit injectors in new engine designs-can still be found in some applications. For instance, some small IDI nonroad engines where low cost is critical and emission limits allow it use relatively simple unit injectors.
What is a UI unit fuel injector?
Unit injectors incorporate the pumping element and the injector in one assembly. In this device-sometimes also called the “pump-nozzle” unit-fuel lines between the pump and the injector are simply replaced by drillings in the UI body. The pumping element is driven from the engine camshaft.
Why add a separate nozzle control valve to injectors?
By adding an injector with a separate nozzle control valve, flexibility similar to that possible with two valve unit injectors becomes possible. Paccar’s MX heavy-duty engine certified to US EPA 2010 emission standards is one application that uses a fuel system based on such an electronic unit pump.