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Fuel Injection Pump - The Heart of the Engine

by LiMona 18 Jul 2023

What is a Fuel Injection Pump?


As the name implies, a fuel injection pump is a device in an automobile that pumps fuel into the cylinders of a gasoline or diesel engine. The injection pump is driven indirectly from the crankshaft by a gear, chain, or timing belt, which also operates the camshaft.


It is usually attached to the camshaft so that they are interconnected. In four-stroke engines, the injection pump rotates at half the speed of the crankshaft to allow the correct injection process timing when the cylinder's compression stroke is about to begin.


This differs from a fuel pump, which is required for fuel to flow from its container or fuel tank. It is part of the system that pumps fuel to the engine block from the tank. Then, the injection pump pushes the fuel inside the cylinder.


It helps deliver precise fuel, maintaining a rhythm or timing and keep the engine running smoothly. Also, the pump controls the amount of fuel required to achieve the desired power. It serves as both the throttle and ignition system needed in gasoline engines.



What is the function of a fuel injection pump?

  1. Pumping fuel at high pressure:

 It is the primary function of the fuel injection pump. The fuel injection pump draws fuel from a fuel tank and pumps it at high pressure to all injectors.

In an electronic fuel injection system, the pump is used only to pressurize the fuel line.


  1. Metering of the fuel:

 The inline fuel injector pump helps control the amount of fuel supplied to the injector.


  1. Distribution of fuel:

 This is another essential function of the fuel injection pump, to distribute the fuel to all the injectors at the exact time.

 In inline fuel injection, each engine cylinder's separate plunger and fuel barrel are used to supply fuel to all the injectors. In the distribution pump, the rotor helps to distribute fuel to all the cylinders.


  1. Cooling of fuel injectors:

 The fuel injectors are directly subjected to the combustion process. Thus the fuel injectors are subjected to a higher temperature. By pumping the low-temperature fuel into the injector, the fuel injection pump helps to cool the fuel injectors.


How to tell if the fuel injection pump is bad?


  1. Engine splutters:

 The improper fuel injection because of the faulty fuel injection pump is one of the reasons for the sputtering noise of the engine. One can notice this sputtering noise while accelerating the vehicle or at a higher engine speed.


  1. Whining noise:

 This is another symptom that you can hear a whining noise made by the fuel pump at the location of the fuel tank.

It may arise due to the faulty fuel injection pump, or it may be due to the insufficient amount of fuel in the tank; thus it becomes difficult for the pump to suck the fuel.


  1. Lack of power when a vehicle is loaded:

 In some cases, when the vehicle is in loaded condition, the fuel pump is not able to provide a sufficient amount of the fuel for the combustion; thus it feels like the engine is unable to produce an adequate amount of power to move the load.


  1. Difficult to start:

 Sometimes it becomes difficult to start the engine, as the fuel pump is not pressurizing the fuel line. In some cases, the engine gets started, and then it again stalls.


  1. Smoky exhaust and less fuel economy:

 One of the reasons behind the smoky exhaust is that the fuel pump is supplying excessive fuel to the injectors. Thus due to the improper combustion of the fuel, smoky exhaust gases are observed at the tailpipe or the fuel economy gets lowered.



What is phasing and calibration of the fuel injection pump?

 Phasing of the fuel injection pump is the procedure of adjusting the fuel injection timing to reduce the torque fluctuations. The phasing of the fuel injection pump is generally done before the calibration.

 The timing of the fuel injection is adjusted concerning the position of the crankshaft. The phasing helps to reduce torque fluctuation. Thus it also reduces the gear impact noise.

 Calibration of the fuel injection pump is carried out to ensure the same quantity of fuel is delivered to all the cylinders of the multicylinder engine. The calibration is generally done after the repairing or rebuilding of the fuel injection pump.




The diesel engine's heart is the fuel injection pump, delivering fuel to maintain the rhythm or timing, which makes the successful running of the machine. If you're aware of diesel fuel injection pump problems with your automobile or have questions about fuel pump replacement components, has the answers you're looking for – and the products, too!

 Here is the link you can check and buy aftermarket Fuel Injection Pump online catalog.

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