How to Clean Diesel Fuel Injectors

How to Clean Diesel Fuel Injectors

Diesel fuel injectors are used to distribute the diesel fuel into the combustion chamber of the engine. The diesel fuel injector is actuated hydraulically to deliver precise amounts of fuel.

They are critical to the combustion process of diesel engines. A fuel injector sprays atomized fuel directly into an intake port or combustion chamber.

When actuated, the diesel fuel enters the cylinder and mixes with the air. This is the basis for combustion that then allows the ignition to take place.

When injectors fail, driving becomes very difficult as it becomes difficult to keep the vehicle on the road, and acceleration degrades due to misfires.

A stuck open fuel injector means that more fuel is pumping into the cylinders than the engine can use; the extra fuel will be dumped into the catalytic converter/exhaust gas recirculation system where it will cause excessive damage.

The more accurate you can control your fuel injection, the better your engine performance and efficiency.

Therefore, it is necessary to clean your diesel fuel injectors periodically to maintain the effectiveness and efficiency of your engine.

Signs That Indicates A Bad Diesel Fuel Injector:

Several symptoms indicate a terrible diesel fuel injector. Some of the main symptoms are as follows:

  • The first and most prominent symptom is the diminishing performance of the diesel engine. This loss of power can be attributed to restricted or clogged fuel injectors
  • Another symptom is the increase in the rate of fuel consumption. Fuel economy will decrease due to poor combustion in the cylinder when using the same amount of the fuel additive
  • The engine sputters and hesitates while accelerating
  • Engine failure to start
  • Excessive smoke from the exhaust pipe
  • Noisy operating engine
  • Lean running engine (refer to your maker’s manual for what this means)
  • Cold starting difficulties while using certain diesel fuels

Methods of Cleaning Diesel Fuel Injectors:

There are several methods that you can use to clean your diesel fuel injector. Some of the popular methods that are widely used are as follows:

  • Cleaning of diesel fuel injector through Ultrasonic Machine
  • Mechanical disassembling for cleaning of diesel fuel injector
  • Fuel Injector Cleaner to clean diesel fuel injectors

Ultrasonic Machines:

The ultrasonic machines are commonly used in the OEM industry to clean hard-to-reach parts. The characteristic of an ultrasonic machine is frequency and energy work together to remove all kinds of dirt, especially for diesel fuel injectors.

The working principle of diesel fuel ultrasonic cleaner is based on the hypothesis that high-frequency ultrasonic waves can remove the solidification and other microscopic dirt accumulation in the fuel system and clean the upper, middle, and lower parts of the diesel fuel injector.

Large deposits lead to uneven distribution of fuel and loss of power. These deposits, either of dirt or fine particles, get burned through ultrasonic waves.

The ultrasonic cleaning process is the non-contact cleaning method. If the ultrasonic cleaning machine is used in the right way, the ultrasonic cleanliness of the fuel injector can reach 99%. It cleans not only the surface but the inside parts as well.

After you practice cleaning your diesel injector through the ultrasonic machine, you need to reassemble it and test if it is working efficiently or not. If it is working effectively, then this makes sure that your diesel fuel injector is adequately cleaned.

Mechanical Disassembling:

Mechanical disassembling is an essential step. You’ll need to take apart the injector mechanical parts. The main parts of diesel fuel injector include:

  • Follower
  • Follower Spring
  • Stop Pin
  • Body Control Rack
  • Gear Retainer
  • Plunger
  • Nut
  • Upper Port
  • Bushing
  • Spring Cage
  • Needle Valve
  • Spray Tip
  • Spring Seat
  • Check Valve
  • Lower Port
  • Filter Gasket

The whole dismantling work needs to be done in a dry place with positive pressure and a dust-free environment.

You need to place all the disassembled parts in an acetone bath and clean each component using a wire brush.

Although this method is less effective because wire brushes may cause damage to the endings and pins of different parts.

Fuel Injector Cleaner:

Fuel injector cleaner, also known as fuel system cleaner, is a chemical used to clean the contaminants that cause poor fuel efficiency or poor performance in most cars, especially the diesel engine.

A diesel engine generates heat through the combustion of the air and diesel oil which causes deposits to form in the combustion chambers. After using for some time, these deposits build up until they are blocking the passageways of the fuel injectors leading to malfunction.

Various methods and substances can be used that serve as fuel injector cleaners, and they will all depend on where they target, how they work and what they do.

The working principle of fuel injector cleaner is to dissolve carbonic acid, sulfurous acid, and acid salts produced in the diesel engine, which obstructs fuel flow. Therefore, ingredients of diesel fuel injector cleaners are different, usually including quaternary ammonium salts, cationic polar alcohols, aromatic sulfides, and other chemicals.

The type of fuel injector cleaner you will use varies and depends on the fuel you use in your diesel engine, the working conditions in which you carry out operations.

Diesel Fuel Injector Cleaning Kit:

Diesel Fuel Injectors cleaning kit is designed to clean the Diesel Fuel Injectors of the diesel engine. If you have a diesel car or van, you need to be especially careful with it.

A cleaning kit is a set of specialized tools used to help you assemble or disassemble your diesel fuel injector and also aid in cleaning the dirt and residue from the injectors and filters in your diesel engine reduces carbon and deposit particles.

It removes all harmful contamination and helps to deliver clean and powerful fuel to the engine.


With this kit, you don’t need any professional off-site if your diesel fuel injector got some problem. You can clean your diesel fuel injector yourself. It helps you to reduce downtime and increases your productivity.

The kit you will purchase for your diesel fuel injector makes sure it is compatible with your diesel fuel injector. Read the manual supplied by the manufacturer to get a better idea about your diesel fuel injector cleaning kit.

Steps to Follow in Cleaning Your Diesel Fuel Injector:

The best method to clean your diesel fuel injector is through a fuel injector cleaner. When you have determined which type of diesel fuel injector cleaner is best for your engine, follow these steps to clean your diesel injector:

  1. First of all, the thing you need to do is start your engine and keep it operating for a few minutes to warm it or to attain an optimum temperature
  2. Secondly, you have to remove the connection of the fuel pump to your diesel fuel injector and switch off your engine and remove the filter that is used to filter the fuel
  3. If you observe that the fuel filter is not good, then replace it with a new one.
  4. Now add diesel injector cleaner or additive to your diesel injector fuel filter
  5. Make sure after the addition of fuel, and there will be no air either inside the filter or within the housing
  6. After adding the fuel cleaner, you have to start the engine again and run it for a few minutes
  7. Now turn off the engine and leave it there for some time; doing this will help the additive to remove the clogged deposits from your diesel fuel injector
  8. After some time again, start your engine and run it for about half an hour to run through the small passages and tiny gaps to clean out the parts effectively.

Following these steps, you can clean your diesel fuel injector effectively.

How Often to Clean Your Diesel Fuel Injector?

The proper cleaning and care of fuel injectors are critical in the upkeep and maintenance of any diesel engine.

If neglected, deposits and varnish can accumulate in the nozzle due to oxidation buildup from varied fuel types and unburned hydrocarbon deposits. The buildup of carbon in the combustion chamber will cause air gaps that slow your engine’s performance.

The cleaning of diesel fuel injectors depends on several factors. The main factors include:

  • Material with which diesel fuel injector is made of
  • The on-site working conditions in which you carry out work
  • Type of fuel or lubricant you are using
  • Maintenance requirements you follow for your diesel fuel injector
  • Age of your diesel fuel injector cleaner

In general, you should clean your diesel fuel injector once in every 30,000 miles drive.

Best Diesel Fuel Injector Cleaners:

There are several diesel fuel injector cleaners are out there. The best ones among them are as follows:

  • Chevron Techron Concentrate Plus Complete Fuel
  • Lucas Upper Cylinder Cleaner and Lubricant and Injector Cleaner
  • Gumout Regane High Mileage Fuel System Cleaner
  • Royal Purple Max Automizer Fuel Injector Cleaner
  • Amsoil Performance Improver

You can select any one depending on your fuel type and injector type.

Precautions to Follow While Cleaning Diesel Fuel Injector:

Preventive measures to be followed while cleaning diesel fuel injectors are as follows.

  • Shut down the vehicle engine. Make sure the vehicle is locked securely so that no one other than you can handle the vehicle.
  • Always keep your body or any valuable thing away from direct contact with the fuel injectors. Be careful of getting your skin anywhere near the injectors because this will cause a severe burning sensation on your skin.
  • Never remove the fuel injector without wearing hand gloves
  • While disassembling, make sure to keep each component of the fuel injector isolated and marked to keep in mind the sequence for assembling

Final Verdict:

Before you start to clean your diesel fuel injectors, you must know why you need to do this. They are responsible for injecting the correct amount of fuel into your engine. This helps the engine run smoothly, keeping costs down and efficiency up.

The right mixture of fuel can prevent dangerous levels of wear and tear on engine parts. When not cleaned regularly, the dirt accumulates inside the fuel injectors might reduce efficiency and increase emissions.

Plus, dirty diesel fuel injectors can create unwelcome noise in your engine. So, before anything else, check if it is time to clean your diesel fuel injector.

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