What are the types of fuel injection methods?

[Katherine]

Fuel injection can be divided into two types based on the injection location: direct injection and port injection. Descriptions of the two methods: 1. Direct injection: Direct injection involves injecting gasoline directly into the cylinder through an injector installed on the cylinder head. This injection system requires a higher injection pressure, approximately 3-5 MPa. As a result, the structure and arrangement of the injector are relatively complex. 2. Port injection: In a port injection system, the injector is installed on the intake pipe or intake manifold, injecting gasoline into the intake pipe or intake port at a pressure of 0.20-0.35 MPa. Currently, port injection technology is widely used in electronically controlled gasoline engine systems.

[KeeganFitz]

I've been repairing cars for over 20 years and have seen all kinds of fuel injection systems. The main types are throttle body injection, port fuel injection, and direct injection. Throttle body injection is simple and straightforward, spraying fuel behind the throttle body, commonly used in older cars. Port fuel injection is currently the mainstream, divided into single-point and multi-point systems, with multi-point having independent injectors for each cylinder's intake port for precise air-fuel mixture control. Direct injection is the most advanced, injecting fuel directly into the combustion chamber during compression, offering strong power and fuel efficiency but prone to carbon buildup requiring frequent cleaning. Direct injection vehicles demand higher fuel quality; good atomization improves combustion efficiency and reduces emissions. I think multi-point injection is sufficient for daily driving—practical and maintenance-friendly. If an injector gets clogged, checking the injection pulse width is crucial; measuring the signal pulse width with a multimeter can diagnose the issue. Don't overlook injector cleaning during regular maintenance to extend their lifespan and keep your car running for more years.

[LaIris]

As a car enthusiast and DIY expert, I've modified fuel injection systems, which mainly include throttle body injection, multi-port fuel injection, and direct injection. Throttle body injection is suitable for beginners to disassemble and install, with simple structure and easy maintenance; multi-port injection has one injector per cylinder to regulate airflow, being cost-effective and ideal for daily use; direct injection is the most advanced, spraying fuel directly into the cylinder to increase compression ratio, providing strong acceleration and noticeable fuel savings. I've tried cleaning direct injection nozzles, which requires precise operation to avoid damaging parts, preferably using an ultrasonic machine. Direct injection also cools the intake air to reduce knocking and enhances overall performance. A small upgrade, like replacing injectors with aftermarket parts, can optimize fuel consumption. During maintenance, using fuel additives helps prevent clogging and ensures stable system operation. Most new cars now use direct injection for better performance, but it's more challenging for beginners, making multi-port injection easier for DIY projects.

[Eileen]

As an environmentally-conscious car owner, I prioritize fuel efficiency. The injection methods include throttle body injection, port injection, and direct injection. The latter is the most energy-efficient, as fuel is injected directly into the core area of the combustion chamber, ensuring complete combustion, reducing carbon emissions, and protecting the environment. Multi-point injection is also decent, as it controls the air-fuel mixture evenly to save fuel. Direct injection enables stratified combustion, optimizing thermal efficiency and reducing emissions, aligning with the trend of green mobility. When choosing a car, I lean towards direct injection technology because its efficient combustion reduces pollution sources, saves on fuel costs, and supports sustainable development.