Check Injectors to Prevent Engine Damage
Check injectors when an FSI, TSI or TFSI engine runs roughly or stores injection faults. We check injectors professionally and explain the results. Request an injector check. Check injectors before consequential damage occurs. Check injectors after recurring injection faults.
When fitting TSI engines we have for some time offered our customers injector testing and cleaning at the same time. But why is that worthwhile, or even necessary?
What Do the Injectors Do in a TSI Engine?
The injectors deliver to each cylinder the quantity of fuel calculated by the control unit. The fuel is injected at a pressure and finely atomised so that it can burn efficiently in the combustion chamber.
Symptoms of Faulty Injectors
A fault shows itself through various symptoms, which may also occur together:
- The engine cuts out unexpectedly or judders
- The vehicle is difficult to start
- You notice a loss of performance
- Fuel consumption is increased
- The idle speed fluctuates
- Emissions performance deteriorates
Faulty injectors can ultimately lead to catastrophic engine damage.
As new injectors are very expensive, it makes sense to have them tested first. That way you identify the faulty injector and can replace only that one. During the test run all injectors are checked for equal flow rate and additionally cleaned ultrasonically. Cleaning can make replacement unnecessary altogether.
Causes of Faulty Injectors
In FSI, TSI and TFSI engines the injector tips sit directly in the combustion chamber – hence the term direct injection. Over time, dirt particles and carbon deposits build up on the injector tip, and the spray pattern gradually deteriorates. In addition, excessive oil consumption causes further contamination.
The Influence of Bio-Ethanol in Fuel
Under EU rules, fuel producers are obliged to use a certain proportion of biologically produced ethanol. In gasoline you can identify the proportion as follows: Super E5 = 5 %, Super E10 = 10 % biological content.
Biological production brings advantages, but also disadvantages: the biological content also introduces impurities into the fuel. The injectors of FSI, TSI and TFSI engines are hit hardest, since after a time they can no longer filter these impurities – the filter screen becomes blocked.
Once the filter screen is completely clogged with small particles, the needle valve no longer opens properly. That valve controls the entry of fuel into the combustion chamber. As a result, the injector no longer delivers the correct quantity of fuel and the engine loses its optimum air-fuel mixture. It is therefore advisable to have the injectors tested in order to detect this process early enough.
The Testing Procedure
During testing, the injectors go through the following stages:
- Assessment of the current condition
- Testing of the solenoid coils
- Leak test
- Checking the spray pattern and injection quantity
- Ultrasonic cleaning of the injectors – contamination and particles are removed
- Renewed check of the spray pattern and injection quantity
- Decision as to whether the injectors can continue to be used
The injectors are subjected to engine-like conditions in a dedicated test rig. This establishes whether they can still deliver the optimum quantity of fuel.
The injectors are subjected to engine-like conditions in a dedicated test rig. This establishes whether they can still deliver the optimum quantity of fuel.
Our Recommendation
When fitting a replacement engine we always recommend having the injectors tested at the same time. In our experience, problems with the injectors frequently occur afterwards without this check. Even without a replacement engine, we recommend testing if your vehicle shows the corresponding symptoms.
Do you have questions, or would you like your injectors tested? Please get in touch.
