How to Determine if the Fuel Injector is Faulty?
3 Answers
Symptoms of a faulty fuel injector are as follows: 1. Engine vibration. When the fuel injector is damaged and fuel injection is obstructed, the engine may exhibit operational vibrations during operation. 2. Decreased power and increased fuel consumption. As the fuel injector deteriorates, the fuel injection volume and pressure cannot be guaranteed, leading to symptoms such as reduced vehicle power and increased fuel consumption. 3. Increased exhaust emissions pollution. Malfunctions in the engine fuel injector will inevitably affect the mixing and combustion of the combustible gas mixture, resulting in increased pollutant emissions from the vehicle exhaust. 4. Difficulty starting or even stalling. When the fuel injector is severely damaged, the vehicle may experience difficulty starting and even sudden stalling while driving. 5. Engine misfire. If the fuel injector of an individual cylinder is severely damaged, the engine is highly likely to experience misfiring, leading to severe engine vibrations. 6. Black smoke from the exhaust. As the fuel injector fails, the atomization of fuel and its mixture with air cannot be ensured, preventing complete combustion of the combustible gas mixture. This results in black smoke from the vehicle and increased engine carbon deposits.
My old car used to have severe acceleration jerks, the tachometer needle danced wildly, the steering wheel vibrated so much at idle that it made my hands numb, and there was always a pungent gasoline smell. The mechanic taught me two DIY tricks: when experiencing cold start difficulties, unplug each fuel injector wire and listen - the silent one is most likely clogged; if black smoke pours from the exhaust pipe and fuel consumption suddenly spikes by 20-30%, it's definitely uncontrolled fuel injector flow. Last time it failed emissions testing, and sure enough when disassembled, two injection ports were completely clogged with carbon deposits, like faucets sealed with concrete. Now I add a bottle of cleaner every 20,000 kilometers as prevention.
Last year, I noticed my car was struggling to accelerate, as if it couldn't catch its breath, and the engine malfunction light was flashing annoyingly. Using an OBD scanner, I detected a P0172 code indicating a rich air-fuel mixture. The mechanic at the repair shop said it was due to leaking fuel injectors. The technician removed all four injectors and tested them by powering them up on a diagnostic machine. One injector was dripping fuel continuously like a leaky showerhead, whereas it should have been spraying in a regular pattern. There was an even more hidden issue—during the fuel injection quantity test, it was found that the third cylinder's injector was delivering 15% more fuel than the others, which explained why the spark plugs were wet and covered in carbon deposits. A word of advice: using fuel from small gas stations for a long time can easily clog the injector nozzles. Since then, I've mostly refueled at Sinopec stations.
