Functions of Fuel injection pumps


The fuel injection pump is a mechanical device that introduces the fuel into the cylinders of automotive engines. It works as a heart of a diesel engine and maintains its rhythm to keep it running smooth for years. Moreover, it is also responsible for controlling the fuel flow to gain the desired power. The fuel injection pump is traditionally driven indirectly from the crankshaft by gears, belts, and chains, anything that drives camshafts.


These are pretty important for diesel engines. By pressurising and injecting the fuel, it throws fuel into the air which is squeezed to high pressure in the combustion chamber. It has four major functions:

  • The major job of injection pumps is to feeds the fuel. It compresses the fuel to high pressure where cam lifts the plunger and then sent it to the injector.
  • It adjusts the fuel quantity. If the quantity of fuel which is injected is changed with engine speed and its timing remains the same, the outcome and the fuel dissipation will change. As the output of the engine is in proportion with injected fuel quantity, this is adjusted with the accelerator.
  • Another important function is to adjust the injection timing. It manages the timing from the point where fuel is injected, ignited and combusted when maximum combustion pressure is reached.
  • Lastly, it atomizes the fuel in order to improve the ignition which results in complete combustion.

Types of fuel injection pumps


Inline Pumps

Often known as jerk pumps, these pumps are built from separate pumps with plunger units connected inline, one per cylinder. Such kinds of injection pumps are activated through a cam mechanically connected to the engine and look pretty much similar to mini inline engines.

Distributor injection pumps

These types of injection pumps have one fuel metering plunger. In these pumps, a spinning rotor makes a hydraulic connection with the different ports on the distributor’s head. Due to the fact that it comes with a single plunger and all the fuel shots are same, these come with the smaller overall package. Moreover, distributor pumps have less moving parts as compared to inline injection pumps.

Common rail injection pumps

In common rail fuel injection, it ost its power to decide when the pressurized fuel will be delivered and at what quantity. It is a direct fuel injection system for diesel and petrol engines.

Electric Pumps

Modern cars come with electric fuel pumps located inside the fuel tank. It creates positive pressure in the fuel lines and pushes fuel to the engine. The cars with electric motor pumps have electronic control unit (ECU) and is programmed with safety logic that will shut it off.

History of Fuel Injection 

The term fuel injection is not a new technology and has been there since the beginning of auto industry. But due to the unreliability and higher cost it came to mainstream in 1980s. With time taking a turn, today’s engine management system combines all the functions including timing, ignition, fuel delivery and cooling in a computer operated technology which allows engine developed maximum power with minimum fuel. It is because of fuel injection system you are able to start the engine instantly during cold days. Without it, we would still be setting choke and warming engines for several minutes and benching out more smoke and pollution.

Important things to know while buying fuel injection pumps

You all must have realized the importance of injection pumps but now the question comes is “how to choose the fight fuel injection pumps?” It is crucial to find the right pump for your vehicle to make it run smoothly for years to come. Remember to go with the pumps that fit your vehicle perfectly. In case the pressure and the flow of fuel are low, then performance and emission related problems likely to happen. There are manufacturers who produce pumps that are compatible with various models and sizes and works under all driving conditions.

Final Words

After knowing the functions and the importance of fuel injection pumps, it won’t be wrong to say that these decide the performance of the vehicle. You can browse through the large fuel injection pump catalogue in order to buy online. Moreover, you can compare the injection pump price in India offered from several manufacturers. The fuel injection pump costs are dependent on whether you are looking for OEM or aftermarket pumps.

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