A clogged fuel injector is usually the result of the fuel filter not doing its job well enough, allowing particles into the fuel injectors. Clogged fuel injectors allow either too much or too little fuel into the engine, causing any number of problems with your cars performance, fuel economy and emissions. If your fuel injectors are clogged, you will need to take your car to an automotive professional and have the fuel injectors cleaned.
Problems Starting the Engine
One of the most common symptoms of a clogged fuel injector is difficulty starting the engine, or the engine not starting at all. Fuel injectors control the amount of fuel that reaches the engine to make your car start, and a clogged injector might be stuck open or closed, delivering the incorrect amount of fuel, or even no fuel at all, when you try to start your car. Listen for your car sputtering when starting, or misfiring as you try to start it, if you believe you might have a clogged fuel injector.
Because the fuel injector controls the amount of fuel reaching the engine when you accelerate or decelerate, you may feel differences in your car's ability to speed up or slow down with a clogged fuel injector. Your engine might surge suddenly, then accelerate too slowly, which is a symptom of too much fuel being injected into the engine. For many drivers, this feels like an up-and-down motion within the car. Alternatively, if your fuel injector is sending too little fuel into the engine, you may experience misfiring. Misfiring generally feels like delayed acceleration, or choppy acceleration when you depress the accelerator.
Problems when idling is another common symptom of clogged fuel injectors. Since idling requires your fuel injectors to send a consistent amount of fuel into your engine over a period of time, it's common to notice problems with the fuel sending system when in idle. Listen for your engine running roughly or violently while idling, a sure sign that the fuel injectors aren't working regularly.
Poor Fuel Economy
Another symptom that may be more difficult to notice but is still a clear sign of a clogged fuel injector is a decrease in your fuel economy. As the fuel injectors become more erratic, fuel may be lost or leaking within your engine. Your fuel injectors might also be injecting too much fuel into your engine when it isn't necessary, which wastes fuel. Pay attention to your gas gauge while driving long distances to pinpoint a possible lowering of fuel economy.