Add to Cart
K4N Used Fuel Injector For Excavator E305SR Square Engine Parts
Specification
Part Name: Used Fuel Injector | Type: Diesel Engine | |
Category: Spare parts | Cylinders Number: 4 | |
Condition: Original Used | Test staus: Normal | |
Type: Direct Injection | Engine Type: Diesel |
Description
Advantages of MPI
Compared to single-point injection or carburetion, MPI engines have
better fuel economy and lower emissions. This is because the engine
can meter the amount of fuel needed for each cylinder. If too much
fuel is added, there are leftover hydrocarbons, and carbon monoxide
is formed from the combustion; if too little fuel is added, the
mixture can explode early, leading to engine "knock." Multi-point
injection, in combination with other technologies, can also improve
fuel efficiency by allowing the engine to selectively disable
certain cylinders during cruising operations when the engine's full
power isn't needed.
How Throttle Body Injection Works
Fuel Delivery
Fuel is delivered to the throttle body injection system by an
electric fuel pump located in the fuel tank. This pump supplies
fuel pressure in sufficient volume to meet the engine's fuel
requirement through all load conditions. Injector pressures range
from 13 to 16 psi (low pressure system) or 35 to 60 psi (high
pressure system), and are kept constant by the fuel pressure
regulator. The fuel pressure regulator is a vacuum-operated
diaphragm, so that during cold start operation maximum fuel
pressure and volume are supplied. Once the engine starts and the
manifold vacuum is available, the diaphragm opens a valve and
allows unused fuel to return to the tank.
Air Delivery
Air is delivered to the engine through the throttle valve. This
throttle valve operates like the throttle valve on a carburetor--as
the throttle is opened, more air is allowed to enter the engine.
Where the throttle body injector differs from the carburetor is in
the area of idle control. Instead of calibrated passages, the
injector system uses a motorized Idle Air Control (IAC) valve. This
valve is in effect a computer-controlled vacuum leak. To increase
idle speed, the valve opens to allow more air in. To lower idle
speed, the valve closes to allow less air in to the engine.