In other articles, we've talked about the different types of fuel injection systems, as well as their pros and cons against the traditional carburetor when it comes to getting fuel into your engine where it can be converted into power and torque. Modern fuel injection systems are sophisticated and rely on a combination of hardware and software to perform the job effectively. Fuel injectors inject fuel into your engine, whether it’s directly or indirectly, and we’ve got a range of the best fuel injectors, as well as fuel injector kits if your ride is in need of a fuel system upgrade.
However, fuel injectors do get dirty over time due to impurities in fuel that can’t be caught by the fuel filter, and knowing how to clean fuel injectors is a skill that can be performed by an enthusiast or a workshop. Let’s take you through what a fuel injector is, as well as the signs of a dirty fuel injector. Then, at the end, we'll also tell you about fuel injector cleaning.
What Is A Fuel Injector?
A fuel injector is a precision-engineered nozzle and electronically controlled valve that is controlled by your car's engine control unit (ECU) to meter out a precise amount of fuel when it receives a signal from the ECU. Fuel injectors may inject fuel into the manifold (indirect injection) or into the cylinder (direct injection). In some engines, fuel injectors fire simultaneously (multipoint), and in others, they fire only when required (sequential). When a fuel injector is dirty, its ability to effectively inject the right amount of fuel into your engine is compromised. So how can you tell if a fuel injector is dirty?
Signs Of A Dirty Fuel Injector
There are several signs of a dirty fuel injector. Early symptoms include less power than usual, as well as poor fuel economy as your engine has to work harder to do the same amount of work. These signs may sometimes be minute enough that the average vehicle owner may not notice, or perhaps considers them normal variation. However, as a fuel injector gets dirtier and more clogged up, more significant effects will result, and those can be apparent to even the most oblivious driver. These include engine misfires, rough idling, dancing of the RPM needle, and the most annoying of them all, a car that refuses to start.
Engine Misfires
Engine misfires occur when a cylinder doesn't experience a bang — that is, combustion of the compressed air-fuel mixture in it when initiated by the spark plug. This can cause the engine to run in an unbalanced fashion, with increased vibrations and reduced power. Misfires may occur at any moment that an engine is operating, but tend to be most pronounced when the engine is under load, such as accelerating or climbing a hill.
Rough Idling
Dirty fuel injectors can also cause rough idling, where your engine struggles to maintain a consistent idling speed. In the best case scenario, you may detect additional vibrations, and your RPM gauge may be indicating a lower idle RPM than usual. In the worst-case scenario, your engine may not be able to sustain itself at idle without you needing to keep your foot on the gas pedal. This can get irritating, especially in a manual transmission vehicle where you need to work the clutch while maintaining pressure on the gas as you brake.
RPM needle dances
Does your RPM gauge’s needle seem to dance around with no connection to your gas pedal input? Are you cruising at a constant speed, maintaining constant pressure on the gas pedal, but the RPM needle seems to be moving around, and you can hear and feel the engine’s RPM changing? This is another sign of dirty injectors, especially when they are injecting varying amounts of fuel due to the clogged nature of the injector.
Car Won’t Start
A car not starting can be for a myriad of issues, including insufficient fuel in the tank, a bad fuel pump, a flat battery, an ECU or sensor issue, or a seized engine in the worst-case scenario. However, clogged injectors can also cause a car not to start. When a clogged injector can't get enough fuel into the cylinders to combust, it means that there's no bang, and the engine won't start. If your car isn't starting because of clogged injectors, it means that the majority, if not all, are severely clogged.
Fuel Injector Cleaning
Fuel injector cleaning is the simplest way to restore health to your injectors and is performed by most workshops. It can also be performed by a knowledgeable enthusiast owner. Cleaning of injectors is usually part of the engine 'tune-up' regimen, and there can be a manufacturer-specified interval for this task. In addition to performing fuel injector cleaning at the recommended intervals, you should also ensure that your fuel filter is clean and undertake a flush of your fuel tank and fuel lines if your car is over ten years old. Don't neglect the fuel pump either, as a weak fuel pump can also present symptoms similar to clogged injectors. There are injector cleaners that can be introduced into your fuel and help clean mildly clogged injectors, but for a badly clogged injector, proper removal and clean-up is required.
JEGS For Everything Performance
Founded in 1960 by Jeg Coughlin, JEGS has been dealing in everything performance-related for a wide variety of vehicles since inception. Now handled by Jeg's able sons, this second-generation business is predominantly e-commerce based with a comprehensive website and online ordering portal. However, if physical purchasing is your thing, there's a walk-in store in Columbus, Ohio. Whatever you're looking for, you're bound to find it at JEGS, backed by friendly expert advice and robust after-sales service. Prices are competitive, and with thousands of products across hundreds of proven brands, the variety is fantastic.
