Blocked prefilters on electric fuel pumps

Information on the product

A blocked pre-feeder pump in a vehicle can cause significant problems in the fuel system. For this reason, prefilters are crucial components in electric petrol pumps. By filtering the fuel, they ensure smooth operation of the supply pump and the downstream fuel system. A soiled prefilter can lead to a rapid loss of power, defects in the high-pressure pump or a faulty ignition.

In both petrol and diesel combustion engines, the fuel pressure can drop due to contaminated fuel, wear or leaks on lines and seals. This results in unstable engine running, noise from the engine, and possibly even difficulty starting the vehicle or the vehicle not starting up at all. In accordance with the manufacturer's recommendations, regular maintenance is required on the fuel filters.

A blocked filter affects not only the fuel line, but all components from the fuel tank to the injection nozzle on the engine. In the repair shop, experts can detect air in the system, defective lines or performance issues at an early stage and carry out targeted repairs.

This article explains other potential causes, problems and repair tips for blocked prefilters on electric fuel pumps.

Product: Electrical fuel pumps

Pierburg no.

E1F:
7.21440.51.0/.53.0/.63.0/.68.0/.78.0

E2T:
7.21287.53.0; 7.21565.70.0/.71.0;
7.21538.50.0

E3T:
7.21659.53.0/.70.0/.72.0

Most modern fuel pumps are flushed through with fuel, which lubricates and cools them. If this does not happen to a sufficient extent, e.g. through soiling, there is a risk of “dry running”. Fuel pumps in the E1F, E2T and E3T series are equipped with a built-in prefilter on the intake side. This small prefilter provides protection against contamination. It can become blocked due to dirt in the intake air.

POTENTIAL COMPLAINTS:

fuel pump does not generate sufficient pressure and shows insufficient delivery rate
reduction in the delivery rate, through to blocking of the fuel pump
dry running of the pump leads to failure
damage to the fuel system
damage to the fuel injection system
fuel pump makes excessive operating noise
fuel pump heats up significantly
engine misfires
premature failure with just a low mileage

Prefilter of the E1F: new on the left, blocked on the right | Pierburg | Motorservice — Prefilter of the E1F: new on the left, blocked on the right

Prefilter of the E3T – blocked by rust | Pierburg | Motorservice — Prefilter of the E3T – blocked by rust

POSSIBLE CAUSES:

In addition to water, impurities are the most common causes for this damage. Possible causes include:

rust formation in the fuel system due to condensate
intake of dirt in the fuel tank from outside (e.g. on refuelling)
ageing of the fuel due to longer periods at standstill (formation of deposits)
maintenance intervals (filter replacement) not complied with
poor fuel quality
old, porous fuel hoses

WE RECOMMEND THE FOLLOWING MEASURES:

Flush the entire fuel system through with clean, quality fuel.
Clean the blocked separator on the intake side (the separator is not available as a spare part).
If necessary, replace the damaged fuel pump. Depending on the degree of soiling, it may be necessary to clean the entire fuel system (e.g. remove and clean the fuel tank too).

CLEANING THE PREFILTER:

Pull the prefilter carefully out of the intake connection with tweezers. Attention: Do not damage the intake connection!
Clean the prefilter in fuel. Attention: Observe the safety regulations concerning the handling of fuel!
Plug the prefilter carefully into the intake connection again. Attention: Do not damage the intake connection!

NOTE:

Observe the following when retrofitting with an electric fuel pump type E1F: For petrol operation, the prefilter can remain in the pump.

For operation on diesel the prefilter must be removed, as problems may occur at low temperatures due to the higher viscosity of diesel.

NOTE:

For type E1F fuel pumps, Pierburg offers a fuel sieve filter (Reference number 4.00030.80.0) that reliably protects the fuel pump from dirt and other foreign particles, preventing premature failure. The sieve filter should be replaced at the same maintenance intervals as the fuel filter.

Video - Electric fuel pumps – blocked prefilter

We need your consent to load the YouTube service!

In order to play YouTube videos, a connection to YouTube must be established. This will also entail data processing and cookie usage by YouTube/Google (possibly also out of the USA). By clicking "Accept", you consent to this data processing and the placing of YouTube cookies on your terminal device. Your selection will be saved for future visits to this website. You may find further information under "More" and in our Data Protection Information.