Disadvantages of Multi-Point Fuel Injection?
3 Answers
Multi-point fuel injection has the disadvantages of relatively complex structure, higher cost, and higher fuel consumption. In multi-point fuel injection, each cylinder's intake port is equipped with a fuel injector, controlled by the ECU for individual cylinder injection or group injection. Gasoline is injected in front of each cylinder's intake, then mixed with air to form a combustible mixture before entering the cylinder. 1. Advantages of multi-point fuel injection: high combustion efficiency, the same displacement can release more power, sequential injection can be adopted, so the air-fuel ratio control is more precise than single-point injection, resulting in better emissions and more fuel economy for multi-point injection engines. 2. Disadvantages of multi-point fuel injection: higher requirements for fuel quality, including engine oil, more complex structure, and thus higher cost.
I have also studied the drawbacks of multi-point fuel injection systems before, and I think the biggest issue is the high cost. Installation and maintenance are relatively complex, requiring multiple fuel injectors and sensors. With more parts, the system is prone to failures, and repairs can be expensive—unlike simpler systems that are more cost-effective. Additionally, the system's complex structure means repair shops need specialized equipment to diagnose issues, such as sensor failures or wiring shorts, and a single maintenance session can cost hundreds of dollars. In certain operating conditions, fuel economy isn't as good as newer technologies—for example, consumption is higher at idle, and carbon buildup can affect performance over time. If you're on a tight budget and want to save money and hassle, this system might not be the ideal choice. I recommend using high-quality gasoline regularly to prevent issues.
After years of driving, I've encountered too many troubles with multi-point fuel injection. The complex system leads to frequent malfunctions, sensors often fail, triggering the engine warning light, and requiring professional inspection, which is a real hassle. The fuel injectors are prone to clogging, and if the fuel quality is poor, they need cleaning or replacement, which is time-consuming and costly. Unstable idle speed and shaking during startup are common, affecting the driving experience. It demands high maintenance from the owner, suggesting checking the circuit during every service. Compared to direct injection systems, multi-point fuel injection is a bit slower in response, making the drive less crisp. If you often drive in the city, these minor issues add up and become truly frustrating.
