How a Diesel Fuel Injection System Works: Understanding Fuel Efficiency

January 27, 2012

The diesel fuel injection system has undergone many changes over the years. Previously, cars used to have a carburetor installed in them, but such cars are no longer on the market. On the other hand, the fuel injection system has been around since the 1950s and electronic fuel injection (EFI) was installed in European Cars during the 1980s. Now, almost all fuel injection service, including diesel injection service and petrol injection service, will supply fuel injection systems. When people think of the word "diesel", most people will think of huge trucks releasing a lot of black soot and gases that cause a great deal of harm to the environment. However, most container ships still rely on diesel to travel long distances across the ocean. Diesel is still mainly used in heavy vehicles like trucks.

Similarity between the Gasoline Engine and Diesel Engine

Both gasoline and diesel engines work roughly the same way. Both of them are internal combustion engines designed to convert chemical energy from fuel into mechanical energy for the car to move. The engine contains cylinders where there are pistons inside that are constantly moving up and down. The pistons are connected to the crankshaft and the up and down motion of the pistons create the rotary movement to move the car forward.

Diesel Fuel Injection System

Both engines convert fuel into energy via a series of minor explosions or combustions. However, the way the combustion happens is different in both engines. In gasoline engine, the air is mixed with fuel and the combined substance gets compressed by pistons. The explosion is ignited by a spark. On the other hand, in a diesel engine, air is compressed first which causes the air to heat up. Then the fuel is injected, which ignites the explosion.

This is probably the way diesel fuel injection systems differs from gasoline injection systems. In the gasoline injection system, all the chemicals are injected first, then compressed. The problem with this system is getting the right amount of compression pressure. If the mixture is compressed too much, what will happen is that the mixture explodes together at the same time, causing knocking. Knocking can damage the engine.

On the other hand, the diesel fuel injector system directly injects fuel into the system. The injector is a very complicated part, and massive research has been done to improve it. The injector can withstand high pressure and deliver the fuel in a fine mist form. Some diesel engines employ induction valves, so that the fuel can get circulated in the engine.

Glow Plugs

Some engines contain glow plugs. The function of the glow plug is to raise air temperature so that ignition can occur in the car engine. Sometimes when compression occurs, no ignition might happen. The glow plugs will then raise the temperature high enough to ignite the fuel.

The Future of Diesel Injection System

In the past, scientists experimented with diesel for fuel energy. The results were disappointing. Burning diesel in a car often gives out a lot of black soot and the engines were giving out loud noises. However, in modern times, an increase in technological advancement has made diesel burning a lot more efficient and cleaner. Direct injections are now controlled by computers.



Related Questions and Answers

How Does Direct Injection Work on Diesel Engines?

In a direct injection engines system the fuel is injected directly into the cylinder in a diesel engine. The injection of fuel occurs when the air is compressed to its hottest and the fuel will work most efficiently. This is the prototype Otto-cycle engine system. A self-igniting system, the diesel relies on the heat generated by highly compressed air to fire the fuel-air mix without the need of spark plug. Because diesel fuel tends to be less refined than gasoline, it also contains anti-fouling and special misting chemicals so the engine will work correctly.

How Often Should Diesel Engine Injectors Be Replaced?

Depending on the type of driving one does, the average life of diesel engine injectors should be about two years before they need a major tear-down and cleaning. This is because the diesel injector puts fuel directly into an already compressed air mixture and it self-ignites (a true Otto-cycle engine). The problem with diesel fuel injectors is not so much the service they are used for but the type of diesel fuel used. If it is high in gums, laqs, and paraffin, you will find that the diesel fuel injector may need replacement more often than you would think.

What is the Most Common Diesel Injector Pump Repair?

The most common diesel injector pump repair is replacement of the pump rotor. The rotor will typically seize due to lack of lubrication. In the majority of cases, this is caused by a clog or restriction that prevents diesel fuel flow from reaching the rotor. Because diesel fuel is similar to oil, it is used as a lubricant for the diesel fuel pump. Another type of problem common to diesel pumps is corroded computer connectors. Because computer control was not part of the original design, the circuit board is sometimes not sealed from the effects of the environment. This is usually the case if the board is mounted below the pump.

What is the Average Price of a Diesel Fuel Injector Kit?

Fuel injector's price can range from $350.00 to $650.00. These kits are designed to provide increased fuel flow, so each cylinder obtains the correct amount of fuel, at the correct time. The injectors found in these types of kits have precision nozzle designs. This means that the orifice has been carefully de-burred, allowing the nozzle to attain drip-free fuel spray patterns. Additionally, the spray pattern will be uniform from injector to injector, ensuring optimum fuel delivery. Most are more durable than the stock injectors that came with the vehicle, and typically provide a 1-year warranty.

What is a Diesel LPG Injection System?

Diesel LPG injection allows the engine to operate on diesel fuel exclusively or a mixture of LPG (Liquid Propane Gas) and diesel fuel. Some vehicles come from the factory equipped to run LPG, while others may need a conversion kit in order to use LPG. Some of the benefits of LPG use are reduced fuel cost, improved emissions, and improved engine power. The LPG is a secondary fuel, almost like a fuel additive. The main fuel delivery system of the vehicle remains unchanged, and the engine can burn diesel fuel as normal. However, when the LPG is mixed with the diesel, it allows the diesel fuel to be completely burned, providing the aforementioned benefits.

Will a High Performance Fuel Pump Make My Car Faster?

The high performance fuel pump is typically a modification that is made as an aftermarket part. However, high performance vehicles come from the factory with these types of pumps as standard equipment. Of course, a high performance fuel pump will be electric, and will be mounted within the fuel tank or engine compartment. However, a high performance fuel pump will not make a vehicle go faster all by itself. Larger fuel delivery lines, heftier fuel rails, high flow fuel filter, and high flow fuel injectors are needed in order to send more fuel into the cylinders, thereby producing more power and speed.

What Do I Need to Adjust the Diesel Injection Pump Timing?

Diesel injection pump timing alterations are made by making cam follower adjustments. For most do-it-yourself operations, and for those not intimately knowledgeable about diesel engines, a diesel injector timing tool set is the way to go. Unfortunately, these tool sets can be very expensive. If you do not do this type of work for a living, you may want to consider renting or borrowing the tools. The kit allows you to measure static timing, determine the injector push-tube travel within the cylinder, and will accurately indicate when the cylinder has reached top dead center (TDC).