The fuel injection system lies at the very heart of the diesel engine. By pressurising and injecting the fuel, the system forces it into air that has been compressed to high pressure in the combustion chamber. . high-pressure pipe – sends fuel to the injection nozzle. injection nozzle – injects the fuel into the cylinder.
In a unit injector, the device is usually lubricated and cooled by the fuel itself. High pressure injection delivers power and fuel consumption benefits over earlier lower pressure fuel injection by injecting fuel as a larger number of smaller droplets, giving a much higher ratio of surface area to volume.
How does a hydraulic injector work?
A hydraulic electric unit injector applies the relationship between force, pressure, and area in order to create relatively high fuel injection pressures from pressurized engine oil. . In a 1:1 system, where the plunger on the oil and fuel sides are of of equal area, the fuel pressure will equal the oil pressure.
How do fuel injection systems work?
In a fuel injection system, there is a special pump that sends pressurized fuel to the engine from the fuel tank. The fuel is kept under pressure and distributed to each cylinder individually. Depending on the individual system, it fires the fuel into the inlet manifold or the inlet port by the use of an injector.
What are the disadvantages of fuel injection?
– Fuel injection system is a complex electronic controlled device that related and connected with few electronic sensors and complex engine control unit.
– Its maintenance or repair scope is very limited and not possible in regular workshop.
– The whole system is quite expensive.
What happens when an injector fails?
If you have one or more faulty fuel injectors — due to wear or mechanical or electrical issues, driving for a long time can cause several problems: Stalling or failure for your car to start. Flooding of your engine. Pre-ignition of your fuel.
What triggers fuel injection?
Mechanical fuel injection The airflow is controlled by a flap valve which opens in response to the accelerator pedal. As the airflow increases, the fuel distributor automatically increases the flow of fuel to the injectors to keep the fuel/air mixture correctly balanced.
How long does a fuel injection service take?
about 20 minutes
How do you know if an injector is working?
I use a screwdriver to test fuel injectors to make sure they are firing. You place a long screwdriver to the base of each injector and put your ear to the end of the screwdriver (like a doctors stethoscope). You should hear constant clicking. If not, then your injector isn’t firing or is firing intermittently.
How does a HEUI injector work?
Opposed to the prior single-shot fuel injection design, HEUI systems use an electronically controlled hydraulic activation with a high-pressure oil pump forcing a plunger within the injector to open the needle to fuel spray into the combustion chamber.
What is the most common disadvantage of direct injection?
The biggest drawback of direct fuel injection is DI can lead to clogged fuel systems and engine carbon fill up.
Is fuel injection more reliable than carburetor?
Again, because fuel injection and modern electronic controls are more accurate, fuel delivery can be tuned to match driver demand. Carburetors are precise, but not accurate, in that they cannot account for changes in air or fuel temperature or atmospheric pressure.
Do you really need fuel injection service?
CARS.COM — Cleaning fuel injectors is a service frequently recommended by dealers and repair shops. But unless there are noticeable signs of clogged fuel injectors (such as a rough idle, stalling, poor acceleration or high emissions levels), it might not be necessary.
Are direct injection engines bad?
The result can be engine hesitation and a loss of power—and the need for expensive repairs. . It involves modifying the engine to spray a small amount of fuel directly onto the valves to help keep them clean. It’s important to note that not all cars with direct injection experience long-term problems.
How do I check my fuel injectors?
How do I know if my injectors need replacing?
– Restrictions. .
– Turbo Troubles. .
– Heat Soak. .
– Increase or Decrease in Long- and Short-Term Fuel Trims. .
– Not Enough Resistance. .
– Longer Crank Times. .
– Failed Balance Tests. .
– Misfire Codes.
Why direct injection is bad?
On certain engines the back of the intake valves and their ports can become coated with carbon deposits. . If enough carbon builds up it can cause rough idling, stumbling on acceleration, stalling, check engine lights, increased fuel consumption and a general lack of power.
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