Before 1980, the most effective way of controlling fuel and air that entered the engine was by mounting a carburetor on top of an intake manifold. With time, technology improved as emissions standards became stricter. Fuel injection then became the universal standard system used solely because it had the ability to control pollutant emissions. It also improved efficiency. That is exactly how the Porsche throttle body assembly came into being. Fuel injection uses it to control the amount of air and fuel that enter the engine. This means that the throttle body assembly is a key performance part in any Porsche model. Read on to learn more.
How It Works
The throttle body is simply a tube that contains a pivoting flat valve (casually referred to as butterfly). Like already mentioned, it controls the amount of air that enters the engine. In Porsche models that are electronically injected, the air flow sensor and the throttle position sensor communicate with the computer which then supplies the corresponding amount of gasoline needed at the injectors. In old carbureted engines, the throttle body is tightly fixed into the carburetor though engine vacuum and mechanical means.
In most fuel injected Porsche engines, the throttle body assembly located between the intake manifold and the air filter. It is mechanically connected to the gas pedal using a cable or in some models, electronically by wire. This means that when you press the gas pedal, the butterfly in the throttle body assembly pivots to allow more air into the manifold. As soon as this happens, the throttle position sensor sends signals to the Engine Control Unit that you have stepped on the gas pedal. The air flow sensor then detects more air and quickly sends a signal to the car computer so as to boost the amount of fuel that is supplied to the injectors.
Always remember that a good air filter is critical to the operation of your Porsche’s throttle body assembly. That’s because dirt build up on the air filter’s surface can easily gum up the butterfly. This will make driving impossible. To avoid this, consider periodic cleaning of the throttle body as well as the butterfly. Be sure to clean the throttle body with a strong aerosol solvent fuel injection/carburetor cleaner and a small brush or a clean, cotton cloth. Pay special attention to the throttle butterfly. Finding it is easy because it is attached with small screws that are stacked to the throttle pivot so as to prevent removal. Remember you do not have to remove it to clean it. As you do this, be extra careful with the Throttle Position Sensor (TPS) on the throttle assembly. Removing it may require recalibration afterwards.
Point To Note
Do not wait until the check engine light turns on so as to service the throttle body assembly or any part of your car. Be keen on signs that indicate something could be wrong with the throttle body assembly. Such signs include poor or high ride or in some cases, vacuum leaks accompanied by an incorrectly adjusted throttle stop.