0

How to check common rail injectors

08.12.2021

How to check common rail injectors

Direct injection technology is the only one that has managed to meet the growing emission requirements. Precise dosing of fuel from the common rail by electronically controlled injectors dominates both diesel engines and gasoline units. But what if the injector is defective? In the following material, we will take a look at the available methods for diesel vehicle injection diagnostics.

Symptoms of injector faults

First we will look at the symptoms that should direct a car user to a service center for injector diagnostics. The primary symptom of an injection system malfunction is improper engine operation. Symptoms may include difficult engine starting, uneven engine operation at idle or under specific operating conditions (e.g., on a warm or cold engine, at certain rpm), noisy injectors, loss of power, excessive smoke.

A defective injector improperly doses diesel fuel into the combustion chamber, causing negative consequences for such things as excessive carbon buildup and clogging of the DPF. Driving with a faulty injection can also strain the engine mechanically, leading to premature wear of its other components.

The importance of diagnostics

We should also go to the service center if there is an error that manifests itself by lighting up the check engine light. However, it is worth remembering that this is not always the case. Diagnostics of injectors is not simple because many components affect each other and often the same symptom can have many different causes.

For example, the problem with starting the engine may relate to insufficient performance of the high-pressure pump, but the cause could also be faulty injectors. It may also turn out that the source of the problem is, for example, a clogged fuel filter, a faulty pre-pump, the wrong fuel, too low a voltage during starting (a weak battery or starter malfunction), as well as the failure of one of the sensors. A good diagnostician will effectively rule out other causes before examining the injection components.

Many people wonder to what extent it is possible to diagnose injectors at home, and although there are not many methods available in these conditions, but some measurements we can make on our car without specialized equipment.

Transfer test

Such a homemade way (also used by mechanics) is to test the overflow of injectors. The injector during operation, a certain amount of fuel taken from the common rail is not directed to the cylinder, and it flows out the so-called. Overflow and returns to the tank. This is a side effect of the injector, which, despite appearances, is a rather complex mechanism.

To make such a measurement, we need to connect the outputs of the overflows to small tanks that allow us to compare the amount of fuel. After a few minutes, we evaluate the results obtained for each injection. Funneling injectors should clearly distinguish excessive overflow from others.

Test in the system

When meeting with a mechanic, we can usually count on reading error codes and an organoleptic examination. Here a great deal depends on experience. The service technician will assess how the engine is running, pick up the characteristic rattle of the injectors, and read parameters related to the operation of the injectors, such as pressure or injector corrections. In the case of common rail injectors, diagnostics is very important because the cost of replacing injection components is significant and runs into thousands of zlotys. Simply removing the injectors involves some risk of damage to them.

What distinguishes a good diagnostician is the ability to combine different methods. There are additional, safe ways to diagnose. An example of such a solution is the measurement with the EDIA-PRO tester, which will help independently evaluate the engine’s performance. This innovative solution makes it possible to observe the parameters of operating common-rail injectors, such as injection-induced pressure drop and engine uniformity. The test is non-invasive and quick. Using such a tool we will find out which injection is knocking, and by additionally measuring the compression pressure we will also learn about the general condition of the drive unit.

Before you decide to remove the injectors for inspection, you can also check them from the electrical side. A tester that will allow you to check the injectors from the electrical side is the SIT-12. In some cases, this is enough to qualify the injector for replacement or to recognize whether the cause of the fault lies with the injector or with the wiring or controller.

Regeneration of common rail injectors

The primary method of testing injectors is to disassemble them and subject them to a test bench. Such a test not only allows you to unequivocally determine the damage to the injectors, but is also a method for confirming the effectiveness of injector regeneration.

For diesel engines, many of the injectors are repairable. Specialized services carefully assess the condition of the injectors, worn parts, such as injection tips, are replaced. In this way, damaged or worn common rail injectors are restored to efficiency , allowing them to continue to operate. An up-to-date evaluation in the form of a test report is attached to the injector. Such an injector, when installed in the car, is supposed to work like new. Well-conducted regeneration of injectors saves the customer and the environment.

GDI/FSI gasoline injectors

Although gasoline direct injection technologies work similarly to those used in diesel engines, injector remanufacturing offerings are smaller. Injector failures are less common. In the diagnosis of gasoline injectors, it is important to take into account that similar symptoms to a defective injector will give a defect in the coil or spark plug. Therefore, the injectors should be considered last.

 

Author: Product Engineer Piotr Libuszowski

Recommended

03.04.2024
The battery – it’s not enough to replace it, it needs to be programmed – part 1.
The battery – it’s not enough to replace it, it needs to be programmed – part 1. I...
20.02.2024
Testing turbine adjusters – a guide to DTE tester updates
Testing turbine adjusters – a guide to DTE tester updates Until recently, th...
24.01.2024
Multimeter or oscilloscope…. How about the QST-5?
Multimeter or oscilloscope…. How about the QST-5? Nowadays, for auto mechanics, accurate diagn...
06.12.2023
Battery testers – why do they show different results?
There is a wide range of battery testing equipment on the market representing different ways of test...
11.07.2023
How to check the sensor with the SENT protocol?
Although it has been several years since the new standard of sensors appeared on popular models, the...
04.04.2023
Diagnostics of the air conditioning system – useful tools
Spring is the time when motorists are traditionally reminded of the air conditioning system and the...
07.02.2023
How do I check the MAP sensor with the QST-5?
MAP sensors are among the basic sensors that have been present in vehicles for years. In the followi...
01.12.2022
How to check the pressure in the common rail?
There are various methods for measuring fuel pressure in a common rail system. In the following text...
11.10.2022
How to check the exhaust gas temperature sensor
How to check the exhaust gas temperature sensor Although hidden from view, Exhaust Gas Temperature S...
08.09.2022
A way out of expensive diesel repairs
Diesel engines owe their popularity among Polish motorists primarily to their lower fuel consumption...
16.08.2022
Soft hybrids in the workshop
Mild Hybrid Electric Vehicle (MHEV) is one of the cheapest and simplest solutions included in the hy...
21.07.2022
Ecology in the car workshop
Many people associate green solutions in the workshop industry mainly with the proliferation of envi...
30.06.2022
How to make money on batteries in the workshop
Although the mechanic’s workshop is increasingly the place to replace the battery, there are s...
07.06.2022
Checking the injector coil with a multimeter and SIT-12
For many people to find that measurements made with different instruments can give results that diff...
19.05.2022
We test the ECU-controlled alternator
The function of the alternator is to produce electricity in an internal combustion powered car. It i...

Why us?

25 years of experience
Over 25 years of experience in the automotive industry gives us the position of an expert who sets trends in innovative car diagnostics. Our greatest pride are hundreds of satisfied customers and numerous industry awards.
The company's mission is "Innovation in Every Car Workshop"
We support car repair shops in their development through education and training, thanks to which we overcome barriers in working with modern car diagnostic equipment
Always close to the customer
Our values inspire us to create devices that create a new workshop reality, giving mechanics a sense of security, the possibility of professional development, independence and increasing profits.

O firmie

DeltaTech Electronics to polski producent i ekspert w branży automotive, który na bazie ponad 25 lat doświadczenia wyznacza trendy w innowacyjnej diagnostyce samochodowej.
To, co nadaje rytm naszej pracy, to wsłuchiwanie się w potrzeby klientów oraz śledzenie aktualnych problemów, z którymi mierzą się warsztaty samochodowe. Owocem tego jest oferta skrojona idealnie „na miarę” ich oczekiwań.

Cały cykl życia produktów od momentu projektowania rozwiązań, poprzez produkcję, kontrolę jakości i opiekę posprzedażową odbywa się w Firmie. Jakość tego procesu dokumentują liczne nagrody branżowe.
Naszą dumą jest szybkie wsparcie techniczne, polska jakość oraz setki zadowolonych klientów. Firma współpracuje z kluczowymi dystrybutorami w branży motoryzacyjnej.

Czytaj więcej

2024 DeltaTech Electronics. All rights reserved.
Skip to content