Injector is an injection or a spray of needles with a solenoid controlled by the ECM. Based
on the amount of air in and rev the engine, the ECM calculates the
basic fuel injection time, and calculate the exact length of time the
fuel injection based on engine coolant temperature, the feedback signal
from the oxygen sensor for closed-loop-control, including the condition
of the vehicle speed and acceleration deceleration, as well as battery
charging status, with the aim of controlling the injector through a
constant pulse signal, and controlled injection pressure to remain
constant. Then the amount of fuel injected is determined by
the length of time through work penginjeksian fuel solenoid holding the
needle valve to open, using Pulse Width Modulation (PWM) sent from the
ECM. The longer the time of fuel injection (pulse width longer) then sprayed the fuel injector will also be increased. Based
on the description above, it can be concluded that the work system is
electronic fuel injection: injection influenced by the injector. The
amount of fuel is sprayed is determined by the length of time the
injection by the injector is calculated by the ECM based on the quantity
of air that comes in, and the condition of the vehicle. Generally
there are two types of injection systems are used: - MPI (Multi-Point
Injection) - SPI (Single-Point Injection) Both systems require a fuel
pump at all times to send fuel to the engine through the fuel filter
from the fuel tank. Fuel pump can be installed inside or outside the fuel tank. Injectors
inject fuel in the intake manifold, and the system pressure is
regulated by a pressure regulator so that the pressure remains constant.
In the SPI system, steam is injected by a fuel injector that is located in the middle of the throttle valve. Distribution of fuel-air mixture is distributed to each cylinder will be reached in the intake manifold. For now the system is no longer used because the distribution of the fuel injection is not good. For
the MPI system, each cylinder has an injector, which is mounted in the
intake-manifold and inject it into the intake valve of each cylinder. Supply of fuel to each injector fuel rail count. 1)
MPI Using multiple sensor system, MPI system continuously measures the
condition of the engine, and calculate the exact quantity of fuel rely
on ECM whose size is set in advance, so the number of supply being
optimal. That's why the engine output, torque engine,
emissions, and fuel pamakaian vehicle capabilities can be provided
according to the design needs of the engine. Fuel quantity
has been calculated will directly sprayed into the intake valve engine,
and only the air that passes through the intake manifold only, so as to
increase flexibility. MPI system has several advantages
compared to a carburetor system, and has been used since 1980, while the
advantages are as follows: 1. Count the quantity of fuel
is very accurate either in stable condition or not (acceleration
increases, the better the machine heating, etc.) 2. During the distribution of fuel in the intake manifold, there is no residual fuel on the wall inside the intake manifold. 3. Distribution of fuel when the load accurately vacant 1. The design can be more flexible intake manifold 2. Using a simple control loop lambda and effective 3. Emsisi endah 4. Lelbih
easily diagnosed and repaired Advantages above can increase the number
of variables that exist on the machine and would also increase the
output is high. However, if the settings for idling is not good, it could result into a weakness. 2)
System SPI SPI system was first introduced in 1979 by GM and Ford, and
successful use by Chrysler in the USA and Mitsubishi in Japan. Outstanding brand is Bendix, Bosch, Hitachi Holley and the specifications of each. SPI
System uses a single injector (for two-barrel intake manifold V6 or V8
engine using two injector) to inject the fuel through the top of the
throttle plate. In this type of injection, fuel is injected
through the gap between the throttle plate and the wall of the intake
manifold, so the shape is conical configuration. Figure 2-1 (b) is a typical illustration of the fuel supply system configuration SPI. SPI has some of the same advantages of the system MPI. SPI
system which measures the amount of fuel based on the exposure time or
frequency penginjeksian injector opening, to facilitate control of
computers and provide an accurate measure of the fuel. In
addition, this system has advantages in terms of istalasi, terturup
looping controls, more easily diagnosed and repaired, as well as having
the character of a small-scale measurements when idling with one point
penginjeksian. SPI system also has the same drawbacks of the system carburetor. Namely, there is a lack samaa distribution between cylinders, and fuel supply could be too late. In this system an active injector increased range and low fuel pressure when the warming-up process, it can reduce performance. Excellence SPI system is compared to a carburetor system is in terms of performance and emissions control.