The fuel injector is the part in your engine that mixes air and gasoline and sprays this mixture into the engine's pistons. The fuel injector has small holes that can clog and cause your car a variety of issues that, if you notice them early, can save you a considerable amount of money in auto repair.
A clogged fuel injector will cause a lag in fuel injection where not enough fuel will reach the engine, causing a loss in engine power. The decrease in gasoline inside the pistons translates to less power, because with less gas to burn there is less heat and pressure created to move the pistons and consequently move the car.
An engine misfire sounds like a gunshot just went off inside of your engine. Your car's internal computer carefully coordinates the movement of the pistons in your car. The computer uses expected levels of fuel to estimate how much power each piston will be creating. It then adjusts how much fuel to put into each piston to make the engine run smoothly and efficiently based on these estimates. However, when a clogged fuel injector injects too little fuel into one of the pistons, its power can differ significantly from the computer's projections and cause an engine misfire.
Your car is idle when the engine is on but your car is in park. A clogged fuel injector can cause the spray of fuel to be erratic as well as slow, and when your car is idle your engine's revolutions per minute (RPMs) may begin dipping and coming back up because of the clog.
When your fuel injector is clogged and spraying erratically into a piston in your engine, there is a difference in power output between that piston and the rest of the engine. Instead of causing a misfire, this power difference can instead lead to your engine or entire car shaking quite vigorously while you are driving or idle.
