Among engines, one major difference between Diesel and Gas is the injection process. Injectors are of two types; one is the Carburetor and the other is Port Injector. Carburetor is a system where the air and fuel are mixed together in an internal combustion engine. Whereas Port Injectors are external (meaning outside the cylinder) and injects fuel prior to intake stroke.
This process is called the Fuel optimization. A diesel engine system looks at optimizing fuel and air before they are injected into their respective chambers.
The basic design mechanism of diesel fuel system has the fuel supply line, an intake valve, an exhaust valve and the fuel injection apparatus. There are also there cylinders attached to its supply line. Fuel passes through a filter and then goes through these lines to the injector device attached with the cylinder. Finally, when the fuel reaches the injector, it is highly pressurized. Diesel fuel is sprayed into the chamber by the diesel injectors. The intake valves suck air into the cylinder and exhale value removes the emissions.
Diesel engines use the direct injectors (directly into the cylinder). Diesel fuel injectors are the most complicated ones and are found in various places in an engine. They are designed to be able to withstand the pressure undergone within and be able to deliver fuel efficiently.
One main drawback of these diesel fuel injectors is when compression of fuel and air limits the compression ration of the engine. That is when the compression is too high, the fuel and air mixtures ignites and causes Knocking. Knocking can damage the engine easily due to excessive heat. Loud noise is also one of the draw backs there direct diesel fuel injectors make.
There is always a solution to every problem; some diesel engines contain these components called Glow Plug. These glow plugs see to that the compression is not too high and prevents fuel from being ignited. Glow plugs are used in smaller engines. Larger engines use ECM, which have the ability to sense the air temperature and sprays the fuel when the engine gets too cold. This facilitates the engine to start without trouble during cold climates.
Over the years, these diesel injectors have become extremely sophisticated. These injectors have become computer regulated. Everything has become completely programmed. The injection timing and fuel amount are all electronically controlled.