How to Maintain Your Fuel Injection System

Fuel injection systems are used in a variety of different industries. One example is the construction industry. Many of the machines used for construction run on diesel fuel.

You also have large trucks that use diesel fuel because of its power performance, reliability, lower carbon, and fuel efficiency. Maintaining your diesel fuel injection system can help you spend less time and money having to repair it.

Equipment failures can be expensive, and machine downtime can mean less work gets done. Here’s what you need to know about maintaining your fuel injection system.

How Fuel Injectors Work

An important part of knowing how to maintain your fuel injection system is understanding how it works. The function that diesel fuel injectors perform is they pressurize diesel fuel, and then pump it through a fixed or electronically controlled opening.

The fuel gets delivered to the engine as a spray, which makes it easier to be ignited than a heavy stream. Additionally, the spray can burn more evenly and efficiently.

It’s this process that becomes less effective when diesel fuel injection systems aren’t maintained properly. The issues that most commonly affect fuel injection systems include water or air in the system and clogged fuel injectors.

If you suspect these could be issues with your vehicle, before you check or address them, it’s important to always make sure you follow any necessary safety precautions to avoid injury. Here’s how you can more safely perform maintenance on your vehicle.

Depressurizing Your Fuel Injection System

Diesel fuel undergoes high amounts of pressure whenever it’s operating. You need to let your engine completely cool and depressurize the fuel injection system before you begin performing any maintenance.

You’ll be protected from any dangerous sprays of fuel when you’re removing the fuel filter. The way you depressurize your fuel injection system is you first have to shut off the engine.

After you’ve shut it off, loosen the fuel filter cap without completely removing it. Be aware that you’ll hear a hissing sound when the cap is loosened. Locate the fittings on the fuel lines and loosen them.

Your owner’s manual should be able to direct you to where they are. Some vehicles place them in the engine compartment, while others mount them on the frame rail of the undercarriage.

After you’ve located the fittings, use a flare wrench and turn counterclockwise to loosen them. The pressure will take a few minutes to release.

During this time, you can clean the spills while waiting. You can then remove the fuel lines completely if you’re planning on replacing your fuel filters. If you intend to do other work, just leave the fuel lines loosened until you’re done with your maintenance.

How to Clean Clogged or Dirty Fuel Injectors

Diesel fuel tends to hold more dirt and debris in suspension easily in comparison to gas. It’s very important to use all the measures you can to keep the fuel injection system and the fuel clean.

The consequence of a dirty or clogged system can mean the fuel will dribble out rather than spray out, which will potentially cause your engine to skip or stop completely.

The general signs of clogging include hard starting, throttle hesitation, rough idling, decreased fuel mileage, black smoke from the exhaust manifold, and pinging sounds.

Additionally, you should be aware that cracked or broken fuel injector system parts can cause similar problems to a clogged system.

There are a few ways you can help keep your fuel injection system clean. First, you should remember to regularly change the oil. Secondly, you should replace the filters on a consistent basis as well.

Lastly, you should consider using high-quality additives designed to protect the parts and keep them clean. The owner’s manual or manufacturer can recommend additives that would work best for your particular machine.

Once you’ve completed this maintenance work and put everything back together, turn the engine on and check for any leakages.

How to Keep Water Out of the Fuel Injection System

When water gets into a fuel system, you potentially risk the engine stopping completely. Many of the fuel filters used today will automatically clog when they’re exposed to water, and this clogging immediately stops the flow of fuel.

It’s necessary to make sure your tank is drained each day according to your machine’s manual. A few signs of water entering your fuel injection system include the engine stopping, the fuel looking dark, sluggish performance, and pressure indicators that show varying degrees of pressure.

There are a few ways you can help keep water out of your fuel injection system. If you have an above ground tank, it’s essential to drain it daily.

You can check for water by extracting a small amount of fuel from your system using a hand-operated bilge pump and putting it into a glass container. When you observe it in the container, check the fuel for discoloration.

Since water is heavier than diesel fuel, it will settle at the bottom if it’s present. In addition, you can look if there’s a dark, thin line between the water and the fuel.

If you do see one, this is a sign that microorganisms have developed, and you’ll need to add a biocide. Make sure you allow the fuel to settle before you begin performing the maintenance.

Let it settle for at least a full day. Pump or bleed water from your tank, and if possible, try to fill up the tank at the end of every shift.

Keep in mind that high-pressure direct injection systems typically return hot fuel to the tank. In general, most systems have fuel coolers to reduce excess heat.

Nonetheless, the tanks still remain above ambient temperatures and will end up holding more moisture than ambient air. As a result of holding more moisture and ambient air, this creates a humid and hot environment in the tank.

As the tank cools off overnight, moisture condenses out, which ends up putting water into the fuel. Refilling your tank at the end of every shift can help push out humid air and limit the potential of water entering the system.

In the event that you keep your fuel in a storage container that’s designed for diesel, be sure it has fuel-water separators that have petcocks at the bottom.

Most of them are see-through, which will allow you to see when the water becomes fully drained. When you’re getting water out of the actual fuel tank, the water can be pumped out from the bottom with an extension hose attached to your bilge pump.

How to Get the Air Out of Your Fuel Injection System

Sometimes, people can accidentally let their diesel machine run out of fuel, which leads to hard starting. It happens because too much air gets into the system, which keeps fuel from adequately flowing and keeps fuel pumps from picking up and pushing diesel through the piping system.

Your maintenance manual should offer you suggestions on how you can properly bleed air out of your fuel system. The way you bleed air out of your system is to first let it cool and depressurize.

Once cool and depressurized, you should put diesel fuel into your tank until it’s filled higher than the fuel filter.

After you’ve filled it that high, loosen the bolt that’s on top of the fuel filter can. This will enable the fuel to push the air up and out. After all of the air has been pushed out, tighten up the bolt.

When bleeding air from high-pressure fuel pumps, crank the engine without starting it to build pressure, and then use a wrench on the injector nut to turn and allow the air to hiss out. It’s necessary to do this on all of your injectors.

In general, the best way to prevent air from getting into your system is to not let your machine ever run out of fuel.

General Maintenance Tips

Remember that your diesel fuel injection system should be properly maintained and cleaned at least every 45,000 miles or 36 months. Some heavy use machines, such as long-haul trucks, may require maintenance and more frequent cleaning.

You can contact your engine manufacturer to learn more about how frequently you should perform maintenance on your machine or vehicle. You should always check your manual for any safety procedure before you begin working on your equipment.

Oil should be changed at the recommended intervals, and fuel filters should be changed every 10,000 to 25,000 miles. Additionally, you can use a wet sponge or cloth to wipe your engine bay, and an old toothbrush to clean the tight corners of your diesel fuel injector system.

Consider using a specialty degreaser to dissolve gunk that could be on your engine or system. Check your owner’s manual to find what degreaser is suitable to use on your system.

Keeping your fuel injector system maintained can save you from costly repairs and losing time completing your work. Be sure to follow these tips so your fuel injector system can run as efficiently as possible.

Fuel injection pumps are also an important part to know more about. There are different kinds of them, such as Stanadyne injection pumps, that can be potentially useful for commercial and industrial applications.

You can find out more information on them at this link:

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