As is with many other facets of an automobile, the modern version of the fuel delivery system is much different than decades previous. As typical as it may be, it is particularly important to be aware of, especially when looking to diagnose a problem. Whether it is for a ’57 Chevy, or a 2010 Toyota, when getting to know the fuel delivery system you are working with, it is imperative that you know its working parts. For the sake of modernity, let’s focus on more modern versions of the fuel delivery system, and the parts that make it function.

Volume and Pressure

In modern fuel delivery systems, the fuel pump is largely driven by the volume and pressure of the gas that is supplied by the fuel pump relay. In essence, it is the job of the relay to create adequate pressure and fuel volume in order to ensure proper fuel pump output.

After the fuel pump relay serves its purpose, next to the part that influences pressure and volume is the electric fuel pump. More specifically, the electric fuel pump effectively creates enough pressure to essentially vaporize the fuel that is being used by the fuel injector. Both the fuel pump and fuel injector are protected by filters — the fuel injector is protected by a fuel filter, while the fuel pump is protected by a fuel strainer, which sifts out dirt as it is attached to the fuel inlet.

Pulse Modulated Fuel Delivery

When getting to know a fuel delivery system it is also important to know the pulse modulated aspect. Essentially, pulse modulation eliminates the function that has traditionally been reserved for a fuel pressure regulator. A pulse-modulated delivery system controls the speed of the fuel pump in order to alter fuel pressure, thus making a regulator largely obsolete. With that said, however, a pulse modulated system does not come full of simplicity, as it needs a diagnostic scan tool, as well as a fuel pressure sensor (utilized by the powertrain control module) to function properly.

The fuel delivery sensors — which are primarily used in pulse-modulated systems — aimed at creating an atmosphere in the combustion chamber that is symbiotic with both air and fuel. Also previously mentioned is the diagnostic system that is built-in with the powertrain control module. Such diagnostic systems are usually quite elaborate and vary depending on the automobile. More concisely, these diagnostic systems are used to not only monitor the performance of the fuel delivery system but also to identify and diagnose any problems that may occur throughout the process of delivering fuel to the engine.