Diagnosing a Fuel Injector Problem

Fuel injection is the method for inserting fuel into internal combustion engines — specifically automotive engines, diesel, and petrol engines (the latter for which fuel injection is an alternative system to carburetors). It is one of the most important and efficient processes in industrial businesses, and is a much easier and cheaper way of powering your vehicles.

Fuel injection as a system harbors a wide variety of benefits for the user. It is more fuel efficient and thereby more environmentally friendly; its two-step atomizer system is much more consistent and smoother during throttle transitions; it can even adjust accurately in accordance with changes and extremes in atmospheric air pressure, temperature, and more, allowing for the engines in question to retain more fuel and adjust injection as needed.

Why Are Proper Care and Diagnosis So Important?

Like any other machine, fuel injectors face a great many potential problems, including clogging, overheating, malfunctioning valves, abnormal levels of resistance, electric shortage, and more.

Signs of a Damaged Fuel Injector

As fuel injectors have become more popular and frequently utilized in various machines, methods of constructing them have become similarly advanced. As such, fuel injectors of today are many times more precise in their methods of dispensing fuel.

With high precision comes great responsibility — meaning that even the slightest deviation from the calibrated measurements can result in electrical problems, fuel issues, or even affect the injector’s drivability. It is of the utmost importance, then, to have your fuel injector running in prime condition.

These are the primary signs to watch out for so you know when you should service or replace your fuel injector:

Clogging as a Result of Heat Soak

Heat soak is one of the most common problems that face injectors. Every time your vehicle’s engine turns off, its fuel injectors leave behind lots of fuel gunk and residue that evaporate, depositing olefin inside the injector. Olefin is a strong, waxy, and fibric substance that one often finds in carpeting, vehicle interiors, wallpaper, and ropes, so you can see why its buildup can be rather problematic for injectors!

Over the months and years, olefin (alongside various other atmospheric particles) can build up in the system and cause severe clogging within. Of course, your injector is bound to become a little dirty as time goes on; this is normal and natural. However, if your daily car use is made up mostly of short trips, then the olefin deposits may well be building up faster than the gasoline detergent additives can cleanse them out.

Since they usually retain the highest temperature after an engine shutdown, the first injectors in your system to fall prey to heat soak are generally the middle (or internal) injectors — particularly in four-cylinder, V6, or V8 engines. There do exist a number of precautionary measures which you can take to prolong the time it takes to clog up the machine.

The most common and effective method is to implement a fuel pressure gauge on your fuel rail test port, turn your engine on, and then read the gauge while utilizing your battery’s jumper wires to jump every injector, one by one, for a couple of seconds. If an injector’s pressure reading drops, it is dangerously clogged, and should be cleaned as soon as possible.

Fuel Injectors That Do Not Open or Close Properly

As a result of clogging from heat soak, fuel injectors may sometimes become so filled with additives or rust they may be unable to close the external valve. Alternatively, many valves fail to close as the result of a faulty spring. The most common result of a valve that cannot shut properly is a gasoline leak.

On the other hand, many fuel injectors do not open because the same external valve may have fused shut as a result of rust buildup or an excess of foreign material. Injectors that cannot properly shut may face increasingly dangerous internal pressure, as well as the possibility of breakage, shorting out, and overheating.

If the valve cannot open correctly, the injector, in turn, cannot drive gasoline through its system. The best way to determine whether your valves are operating properly is to test the ease and smoothness with which they open and close.

Gasoline Leaks

In the same vein, gasoline leaks may occur both externally and internally if the mechanisms themselves fail. If its cooling system breaks down, the injector may face potentially dangerous overheating. On the flip side, the injector mechanism itself could also suffer from broken parts, which would then cause leakage and drastically reduce the machine’s efficiency.

Lack of (or Too Much) Proper Resistance

Your fuel injector generally operates through a solenoid, which projects a strong magnetic field in order to produce enough pressure to lift the injector pintle. Without a high enough resistance, the magnetic field is unable to fully overcome the fuel and spring pressure, and thereby open the injector.

Failure of the fuel injector itself can also cause the magnetic solenoid to short, leading to a problematic lowering of the resistance levels. Excessive amounts of resistance may also result in similar problems; a high current could shut down the primary circuit, shutting down all fuel injectors operating on the same circuit.

These internal shortages are one of the most common reasons for the breakdown of fuel injectors. Internal shorts result in needing greater amounts of amperage. In turn, the engine management computer operating inside many newer models of vehicles will completely shut down the fuel injector in order to maintain proper levels of road efficiency.

Final Thoughts

Fuel injectors are an essential function of the automobile system. Their high levels of efficiency and environmentally friendly nature make them the ideal fuel system for all vehicles, and their consequent rising popularity is proof of their many benefits. That being said, proper maintenance of fuel injectors can be the difference between retaining top efficiency and mileage. Learning to look out for and diagnose the most common reasons for injector failure is the key to keeping your vehicles running — and running safely.

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