
Fuel injectors are not wearable parts and do not require cleaning if the car idles and starts normally. Extended information is as follows: Definition: A fuel injector is essentially a normally closed valve, with its opening and closing controlled by the vertical movement of a valve needle. When the ECU issues a fuel injection command, the voltage signal causes current to flow through the coil inside the injector, generating a magnetic field that lifts the valve needle, thereby opening the valve to allow fuel to spray out through the injection hole. Impact of Carbon Deposits: Clogged fuel injectors can severely affect vehicle performance. The blockage is usually caused by carbon deposits from the engine accumulating on the injectors or impurities in the fuel obstructing the injector's pathways. After a period of driving, certain deposits will form in the fuel system.

Having worked in repair shops for years, the cleaning interval for fuel injectors depends on specific driving conditions. For daily urban commuting, it's advisable to check carbon buildup after 30,000 kilometers. If you frequently use cheap fuel or drive on dusty roads, advance the cleaning to 20,000 kilometers. The before-and-after difference is striking – vehicles with severe carbon deposits will feel sluggish during acceleration, but immediately after cleaning, the throttle response becomes crisp, and cold starts in winter stop shaking. Don't wait until complete clogging occurs, as fuel consumption can increase by two percentage points, and the catalytic converter may suffer. Nowadays, non-disassembly cleaning equipment is widely available, taking just half an hour – far more cost-effective than replacing new injectors.

As a veteran taxi driver with 15 years of experience, I adhere to cleaning the fuel injectors every 20,000 kilometers. Stop-and-go traffic in urban areas particularly accelerates carbon buildup, which worsens with poor fuel quality. Once, I neglected the cleaning, and suddenly the engine warning light came on during operation. When towed to the repair shop, the injectors were completely clogged with black deposits. Nowadays, I use diagnostic computers during maintenance to check injection data—if atomization is uneven, it's time for cleaning. Additionally, I recommend adding a bottle of genuine fuel additive every 5,000 kilometers, which can extend the cleaning interval to 30,000 kilometers. For those who frequently drive on highways, carbon buildup is slower. For instance, my partner who operates interprovincial routes cleans the injectors only every 30,000 kilometers.

For the first three years of a new car, there's generally no need to worry about the fuel injectors, as they maintain excellent atomization in their factory condition. After the first maintenance, as mileage increases, slight carbon buildup symptoms may appear: delayed cold starts and minor jerking during sudden acceleration, which serve as reminders for inspection. Maintenance manuals typically recommend cleaning between 20,000 to 40,000 kilometers, depending on the fuel injection system type. For port fuel injection vehicles, cleaning at 30,000 kilometers is ideal, while direct injection engines, due to their high-temperature and high-pressure operating environment, are advised to be cleaned earlier at 25,000 kilometers. Disassembling and cleaning is more thorough than non-disassembly methods, making it suitable for vehicles with severe deposits.


