The throttle pedal is a part of the engine's intake system which regulates the amount of air that's mixed with fuel for combustion. The engine needs oxygen from the air in order for combustion to work. It is imperative that the car's engine is supplied with the correct amount of clean, filtered air. Air needs to be as clean as possible before it mixes with the fuel and burns in the cylinders of the engine. The overall result of this ensures the engine is working to its optimum, providing more power and fuel efficiency. There are many vital components that work together to ensure the air entering the engine is a steady and uninterrupted flow of clean, filtered air, of exactly the right amount.
The throttle pedal manages the throttle valve which controls the flow of air in the engine and in turn dictates the amount of fuel released into the engine. Ultimately the throttle pedal, by regulating the air and fuel flowing into the engine, controls the speed at which the car travels. The throttle pedal is located in the footwell of the car. It's the pedal on the right hand side next to the brake pedal.
When you press down on the throttle pedal, this causes the throttle valve to open up, allowing more air to flow in. The engine control unit recognises that the throttle valve is open and in turn regulates the amount of fuel entering the engine in readiness for the increased flow of air in the engine. In essence, when you press the throttle pedal with your foot, this makes the car go faster.
Problems can occur if a build of dirt or soot causes restrictions in the air flow or movement of the throttle plate. A faulty throttle pedal can get sticky when the throttle valve it connects to, which lets the air into the engine, gets clogged up with waste carbon. In a worst-case scenario the accelerator pedal can malfunction and get stuck fast, but this is rare. throttle pedals do wear down over time, however, and you will eventually need to buy a new part for your car. Symptoms of this will include a sticky throttle pedal or one that's harder to press down with your foot. Generally speaking, if the compression of your foot on the throttle pedal is not a smooth and easy process then you should ask your mechanic if it needs a replacement.