The Fuel System is essential for an engine to run, since it needs fuel, air, and spark. Fuel first enters the gas tank, and is then pumped towards the front of the car via a fuel pump. The fuel then passes through a fuel filter/fuel regulator, which filters particulants out of the gas, and regulates how much fuel is sent towards the engine. The fuel travels through fuel lines up until it reaches the fuel rail. From here, the fuel flows through the rail, and into fuel injectors. They are the final piece of the system, shooting fuel into each cylinder.
When I bought my car, it had a bad fuel pump. This is one of the items I had to replace in order for the car to run. I also replaced the fuel filter, as the car has 140,000 miles. I noticed an improvement in my fuel economy after doing this.
Here is a basic diagram of a car fuel system:
Choosing good fuel itself is also very important. What octane gas do you use in your car?
It may come as a surprise to some, but the different octane ratings do have purpose. The number is the measure of the fuel's ability to resist knocking during combustion. Each car is different, and owners manuals state which fuel you should be using in your own car. Damage can occur to the engine by running the improper octane fuel over periods of time. Additionally, using the correct fuel grade allows you to get the best fuel economy out of your car. While it may be a few more dollars to fill up, that money could be saved in fuel economy. It is also a generally good rule to go to gas stations that are regularly used. This way, you are always getting newer gas that has not been sitting for long periods of time, which can again affect fuel economy.