Diesel Pump and Diesel Engines

Diesel pump or as it is commonly known an injection pump normally is used to fuel a diesel engine, injection pumps can be utilized to deliver gasoline to a petrol engine also.A diesel pump, in the first engines, would have been powered by the engine using a connection directly to the engines crankshaft. The diesel pump will be timed to inject the diesel into the engine at the right time during the pistons stroke.Commonly a diesel engine in your normal car, van or lorry will be of the four stroke sort, larger engines used in ships and big machinery will often be of the two-stroke sort to boost fuel efficiency. Two-stroke engines you would as a rule find in a strimmer or model plane, of course these use petrol to operate.The main variation with a two-stroke engine is that the first and ultimate strokes are completed concurrently, this has the effect of drastically increasing performance at the sacrifice of a dirtier exhaust. Another gain is that two-stroke engines can be easily operated in reverse, providing a reverse function without the need for complex gearing mechanisms.In the current engine there are two main variations of diesel engine, those are the common rail diesel engine and the electronic unit direct injection.An electronic unit direct injection assembly combines the injector and diesel pump into a singe piece, the diesel pump is, commonly, still driven by the engine. An Overhead Camshaft (OHC) drives the diesel pumps and injectors, this is an assemblage sat on top of the engine and connected directly to the engines main cam shaft by chain, or more commonly nowadays, a belt.The common rail diesel engine consist of a high pressured fuel rail, basically a manifold, supplying individual diesel fuel injectors as opposed to the diesel pump delivering fuel directly to the fuel injectors.As stated, above, your modern diesel engine works on a four stroke sequence. You might have heard this called the Otto cycle after the inventor of the petrol motor, Nikolaus August Otto in 1876. A few years afterward Rudolf Diesel arrived and, wishing to construct a more fuel efficient motor, came up with the diesel engine in 1892.Diesel engines have been a bit slow on the up-take, for the typical family car, chiefly due to their repute of being noisy and smelly. Clearly this is altering as recent technology makes the diesel engine a more agreeable answer to our present transport woes.The four separate events or strokes in a mainstream four stroke diesel engine are as follows:The Intake Stroke: As the piston reaches the top of it’s stroke and starts to move downward the air intake valve is opened, this has the effect of air being drawn in as the piston moves downward.The Compression Stroke: As the piston hits the bottom of it’s stroke the air intake valve will close, as the exhaust valve is also closed the air enclosed in the piston chamber is compressed as the piston moves back up the shaft.The Combustion Stroke: As the piston hits the top of the compression stroke diesel is injected at the exact moment by the diesel pump and as the piston is fractionally past the top of the upward phase of the compression stroke the fuel to compressed air mixture is ignited. This is where the energy to drive the vehicle is produced, the piston is forced downward driving the engine.The Exhaust Stroke: For the duration of the pistons last upward stroke the exhaust valve is opened and the gases created from the ignition of the air to fuel combination is pushed out and into the exhaust mechanism. At the end of this stroke the four strokes are concluded and the entire cycle starts again from the start.One downside to diesel fuel as opposed to petrol is when used in very wintry climates. Diesel will begin to freeze at a higher temperature than gasoline, this will start off by the diesel becoming denser and waxy, clearly this will inhibit the good running of most diesel engine. One trick is to put a tiny amount of petrol into the diesel fuel combination to help lower the freezing point of the overall mixture.This also has the added advantage of making the overall combination more flammable, although too great a mixture can damage a diesel motor, even small amounts of petrol in a common rail engine can bring about critical problems so seek advice from an experienced mechanic prior to varying your fuel mixture.Another issue that can be effortlessly spotted is if your diesel pump is not working, this has the effect of reduced fuel supply or pressure to the fuel system. Basic signs are a failure of the engine to start, a lumpy or noisy ignition, or a high pitched whining coming from the motor. You will probably also notice a lack of performance when applying the throttle.If any of these situations arise it would be recommended to get your car tested by a mechanic who may need to find you a new diesel pump.

[phpbay]electronic,10, “38635”, “”[/phpbay]


More Details Below







This entry was posted in Auto Part and tagged , , . Bookmark the permalink.