What are the disadvantages of multi-point injection?

The disadvantage of multi-point injection is that it requires high oil products, including engine oil; The structure is complicated, so the cost is high. Multi-point injection is equipped with an injector at the air inlet of each cylinder, which is controlled by the electronic control unit and injected individually or in groups in different cylinders. Gasoline is injected in front of the air inlet of each cylinder, and then enters the cylinder together with air to form a mixed gas. Multi-point injection is relative to single point injection Single-point injection means that only one nozzle is responsible for injecting oil into each cylinder. The nozzle is located on the intake pipe, and its injection quantity depends on the throttle valve before it is divided into the intake manifold. Due to the different length and position of intake manifold, the amount and time of mixed oil and gas injected into each cylinder are also different, resulting in different working conditions of each cylinder. The advantage of multi-point injection is that it can realize accurate injection by precisely controlling the oil pump of the driving computer, which is also a weapon for automobile manufacturers to replace carburetor to meet strict emission requirements. Secondly, the combustion efficiency is high, and the same displacement can release more power. And sequential injection can be used, so the control of air-fuel ratio is more accurate than that of single-point injection, so the multi-point injection engine has better emissions and is more economical and fuel-efficient.