Common fuel pump defects and how to discern them - AutoNorma

Common fuel pump defects and how to discern them

Injection fuel pump is one of the key components of a combustion engine and a rather pricey part to be replaced should it become defective. The main role of an injection fuel pump is, under high pressure, to dose fuel from the fuel tank to the combustion spaces of the engine. Often times it works reliably and it is not an exception for such an injection pump to outlive the rest of a vehicle. However, that is not always the case. That is why we are bringing you this article in which we will cover some of the most common causes of defect on this unique part assembly.

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Fuel pump types

  • fuel pump located inside the fuel tank

  • injection fuel pump which is a part of the engine block

How does the fuel pump work?

The job description of a fuel pump located inside the fuel tank is fairly simple. First, the electromotor spins the turbine blades, which in turn makes the turbine suck fuel from the fuel tank; the fuel then proceeds through a filter and is pumped directly to injection fuel pump. The injection fuel pump then pushes the fuel through individual injectors all the way to the engine cylinders. The adequate pressure conductive to this whole process is continuously maintained by the pressure valve. In some cases, the fuel pump normally located inside the fuel tank is replaced by an underpressure dosing pump embedded inside the injection fuel pump.

How does the injection fuel pump work?

Propulsion of the pump is facilitated either by the engine's camshaft or by an independent propulsion mechanism inside the injection pump. Piston pump is the most commonly used type of an injection pump in today's vehicles. Finally, the injection pump cools and partially lubricates the fuel (diesel a little bit more than petrol).  

Most common injection fuel pump defects

Among the most common causes of injection fuel pump defects is generally contamination of the fuel circuit with corrosion, dirt, or perhaps sediment from the fuel tank or the fuel filter. Furthermore, it could be:

  • injection pump control unit fault (if the unit is present construction-wise)

  • injection pump sensor fault

  • fuel-dosing valve fault 

  • injection pump distributor head fault

  • injection pump body fault 

  • damaged valve regulator 

  • damaged shaft

How to discern that the pump is indeed defective

  1. unresponsive engine, or tough start

  2. shutting down of the engine - due to unsufficient amounts of fuel pumped in the circuit, the engine will shut down shortly after start or as soon as the throttle pedal is pressed

  3. low driving comfort - spikes when accelerating due to low fuel flow in the circuit, insufficient power due to insufficient fuel pressure, engine spikes, disturbing noises 

How to prevent fuel pump from becoming defective

  • maintain the fuel pump together with the entire fuel system in good and clean condition

  • do not drive with almost empty fuel tank

  • pay attention to the quality of fuel and the fuel octan number 

  • regularly inspect the fuel filter and be sure to replace it should its condition require 

  • regularly inspect the fuel tubes, electrical connection; be on the lookout for any freshly-formed cracks or imperfections and other types of damage that could possibly lead to a defect on your fuel pump

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Replacing your fuel pump with a new one 

Before you opt to mount a brand new fuel pump onto your vehicle, it is imperative to run the vehicle through proper diagnostics to either confirm or rule out that the engine troubles are indeed caused by defective injection fuel pump. Should the diagnostics confirm that it is necessary to replace the injection fuel pump, be sure that the entire fuel system--including the fuel tank--is clean and contamination-free. Finally, should you desire to save on money, but not on quality, consider purchasing a remanufactured pump. In this article, you will find out more about our remanufacturing procedure. 

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