All the Important Parts You Need To Know About In Diesel Fuel Systems

The main job of the fuel system in a diesel engine is to inject pressurized and atomized fuel into the engine cylinder. When this fuel meets hot air, it combusts, which makes the engine work. Here are the primary parts that make up this system.

Fuel Tanks

Fuel tanks are available in plenty of different sizes and shapes. That’s because each one has a specific purpose, with some being built for diesel and others being built for alternative fuels. For example, in a diesel system, the tank will be big enough to store the fuel required to operate the vehicle for a reasonable amount of time.

Aside from this, it must be covered to protect the system from picking up foreign materials. On the top, there is a vent that allows air to enter the tank. There will also be openings to fill, discharge, and drain the tank.

Fuel Lines

You will find three types of lines in diesel systems. Heavy-weight lines run to the injectors from the injection pump, medium-weight ones run to the injection pump from the tank, and light-weight lines run everywhere else.

Fuel Filters

Unlike gasoline, diesel needs to be filtered several times. Most engines have three filters, a screen in the tank and a primary and secondary filter. For most systems, these are arranged in series, so the diesel goes through each one separately. However, parallel setups are also an option, so different fuel goes through the appropriate filter.

Fuel Transfer Pumps

The most basic systems use air pressure or gravity to move the diesel to the injection pump from the tank. Fortunately, today’s systems use a transfer pump to speed this process up. This pump, controlled by your gas pedal, moves an exact amount of fuel to the injection system. These typically use a cam and plunger method to move the fuel. However, they can’t have air in them and are equipped with a primer to remove any air that may have gotten in.


The most common problem for diesel fuel systems is water. However, it is also pretty common in diesel fuel. When you use low-quality fuel, you can often put water into your system, which can cause the metal parts to rust. This can lead to injection problems, sticky metering, and system failure.

Fuel systems are a critical part of diesel engines. They consist of many components. While some are similar to what you find in a gasoline engine, others are different. Some components can even cause problems to the entire system.

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