As the name direct injection suggests, fuel is pressurised and sprayed into the combustion chambers of the engine. The injectors play a vital role in this and if they clog up, the performance of the car drops.
Possibly the most intriguing fact about injectors is just how small the nozzle is. The diameter of a typical nozzle found in the injector of a car is about 150 – 200 microns wide. For comparison, the diameter of a human hair is about 80 microns. When fuel gets injected into the combustion chamber, it is not just about the right amount, but also to provide an even distribution of the tiny fuel droplets to ensure an effective, even ignition and combustion.
The fuel pressure, when starting the engine, ranges typically between 200–250 bar for hole-type injectors and can range from 300–2000 bar for diesel injectors. As Diesel engines are based on a different principle, the pressure needs to be higher than in petrol engines. Nevertheless, they can clog up too.
Engine injectors clog up primarily due to the buildup of carbon deposits, dirt, and other impurities present in the fuel. These can accumulate over time, especially when using poor quality fuel. To counter this, some modern fuels contain additives to help keeping the injectors clean. Especially driving short distances that don't allow the engine to reach optimal operating temperature contribute to the carbon deposits in the injectors.
The most common problem is fuel containing debris, dirt, rust, or even water. These pollutants can get trapped in the injector and clog it up. Although these pollutants may pass through the fuel lines, they can get stuck in the bottleneck that is the injector nozzle. When examining the injector system, attention should be given to the air filter as it is another way contaminants can enter the system.
Injectors need very little attention. Only every 30 000 – 40 000 would they need to be cleaned. Using high quality fuels, containing additives to keep the system clean already helps slow down or prevent carbon deposits in the injectors. Should the injectors need cleaning, German Motors recommends using specialised products, meant to be used for this purpose. Injector cleaners are fluids that are added to the fuel, cleaning the injectors as they flow through them. With the injectors being delicate technical components, it is crucial to ensure that the right products are used. At times, as colleagues at German Motors know, regular long-distance trips can also help to release the carbon buildup.
In case the treatment with injector cleaners does not yield the desired results, owning to very strong build-up of carbon, the help of professionals may need to be called for. Specialising in the professional cleaning of injectors, these technicians can work wonders, restoring the performance of the injectors.
To avoid costly, premature repairs or replacement of the injectors, one should adopt a defensive driving style, use quality fuels and have the injectors cleaned professionally. German Motors staff will be able to work out a maintenance schedule for you, should you wish to introduce this into your regular services.
