What is a plunger pair?

high pressure fuel pump (pump) - is one of the most important nodes of any diesel engine.It is through this part of fuel is supplied so as to enter the camera is not a liquid, and fuel-air mixture.At work significantly affect pump plunger pair.With this item is performed and distribution of fuel supply to the engine.And today we will look at what the plunger pair, how important it is for a diesel vehicle.


design of this element implies the existence of two main elements - the sleeve and the plunger.The latter consists of a small piston of a cylindrical shape.When the pump This part moves inside the sleeve.Due to the reciprocating movements which they produce, fuel injection is carried out, after which the fuel is sucked.Steam plunger pump (photo of the item you can see below) has holes on the sleeve.Through them comes the supply of diesel fuel injection.

That is the main purpose and function of this element is to measure the precise amount of fuel for its delivery to the engine cylinders.I

n addition, by using this pump element feeds fuel under a predetermined pressure at the right time.But in order to carry out these operations without failure, the plunger pair must meet a number of technical requirements.The very same its production is carried out on high-tech equipment (usually in large enterprises).At home, it is impossible to make such an element.About

injection valve as an integral part of the fuel system

main objective of this element is overlapping routes of high pressure between the plunger and fuel.This gives a reduction of fuel pressure that is necessary for a more accurate and faster closing spray nozzles.This prevents the formation of fuel droplets, and their presence therein is highly undesirable.During the injection the pressure that is created in the space above the plunger produces a rise of the discharge valve cone.Further, the fuel pressure falls to the gun through a fuel valve and holder.Once the plunger groove opens the spill passage, the pressure level in the chamber drops and the spring pushes the discharge valve device body to the seat back.This action takes place in the system as long as the plunger does not start a new stroke.

Chance of whether leakage of the plunger?

in detail the likelihood of leakage of high-quality fuel is zero.To minimize the chance of fuel leakage, the gap between the sleeve and the plunger is made to be 1-3 microns.Due to such a high accuracy each plunger is chosen individually to the hub.After this is done at the factory fitting both parts.During fabrication of these surface elements further tempered.This is done in order to maximize long-term operation of the part.

Operation details

plunger pair - this is the element that requires special attention during the operation of the vehicle and its fuel system operation.The pledge of quality and uninterrupted operation of this part - the use of only high-quality fuel.Unfortunately, the quality of domestic fuel gas station next few, so our car owners (especially those with diesel engines) is often necessary to repair and clean the nozzles.

different chemical contaminants and a large concentration of dirt and deposits significantly reduce the life of the plunger.
particularly negatively affected water, which is also sometimes found in domestic fuel.When it gets into the gap between the sleeve and the plunger, the integrity of the lubricant film is broken, causing the device begins to operate without lubrication.This can lead to increased heating, deformation, and even jamming of such details as the plunger pair.In this case, out of the situation is only one - the replacement of a new device.To avoid such trouble, you need to regularly diagnose fuel equipment and if possible not to refuel at gas stations strangers.

When the plunger assembly must be replaced?

There are several major symptoms indicate a problem with the part.One is the failure of the engine is started.But the failure to determine the plunger assembly is possible and with the engine running.In this case it is necessary to pay attention to the performance of the motor.If it is unstable and intermittent, probably, the reason lies in the fuel system.Also, if a faulty pump element motor starts to lose its capacity considerably and to publish other sounds that were not previously encountered.If you notice at least one of the above symptoms, it is necessary to diagnose the fuel system of the car.

worth noting that you need to have a special diagnostic equipment.Therefore, with their own hands and without the proper equipment, you are unlikely to be able to determine if the plunger.After the diagnosis the master decide whether there should be any adjustment of the plunger assembly should be replaced completely with the new.When repairing certain equipment used that restore the original dimensions of the plunger and sealed sleeve.The very same replacement also requires special care, knowledge and experience, so do something with their hands in the pump is extremely dangerous, as it could damage the entire system in a car.

Conclusion So, we figured out how to influence on the pump plunger pairs and all of their design features.In general, the fuel system of the diesel internal combustion engine - a very complex mechanism that requires special attention and maximum quality fuel.In this regard, the number of diesel cars in our country is much lower than in Western Europe.After all, with their hands to serve fuel is almost impossible, and regularly spend money on costly repairs and diagnostics hardly anyone wants.