What are the symptoms of dirty fuel injectors?
3 Answers
Symptoms of dirty fuel injectors include: increased engine noise, unresponsive throttle, uneven acceleration, and minor idle vibration. The cleaning method for fuel injectors is: 1. Hang the cleaning device on the front hood of the car; 2. Locate the engine's fuel supply and return lines; 3. Disconnect the return line from the engine and use an appropriate plug to block the return line; 4. Connect the fuel supply line to the outlet of the cleaning device; 5. Open the fuel tank cap and remove the fuel pump fuse to stop the fuel pump operation, completing the process. The fuel injector is located on the intake manifold or directly on the cylinder for direct injection engines. The fuel injector is a simple solenoid valve. Its working principle is: when the solenoid coil is energized, it generates magnetic force, lifting the needle valve to open the injection port. Fuel is sprayed at high speed through the annular gap between the needle valve head and the injection port, forming a fine mist for optimal combustion.
When I found the fuel injectors were dirty, the car was particularly hard to start, and it failed to ignite several times. The engine shook violently at idle, like it was coughing. There was no power when accelerating, and it took a long time to respond after stepping on the gas pedal, making overtaking difficult. Fuel consumption also increased significantly—previously, a full tank could run 400 kilometers, but now it's down to around 360. Sometimes, black smoke comes out of the tailpipe, and the smell is strong. All these issues are caused by carbon deposits clogging the fuel injector nozzles, leading to uneven fuel spray. Adding a bottle of fuel additive each time I refuel can alleviate the problem a bit, but if it gets severe, I need to go to the workshop to clean the fuel injectors. Otherwise, performance will continue to deteriorate, affecting the overall engine lifespan. Regularly driving on highways can help prevent carbon buildup.
Having driven for over a decade, I can tell you that dirty fuel injectors manifest as frequent engine misfires, especially during low-speed starts when RPM fluctuates erratically, and unstable idling that feels like dancing. Cold starts become extremely difficult, requiring three or four attempts before the engine fires up. Acceleration response slows to a snail's pace—you press the gas pedal, but the car hesitates before moving. Fuel consumption noticeably increases, costing dozens more dollars per week on gas. Exhaust sometimes turns black and emits foul odors, which is also bad for the environment. These issues are often caused by carbon buildup from poor fuel quality or prolonged short-distance driving. I recommend regular inspections and using professional cleaning agents every 20,000 kilometers to prevent more complex problems.
