Keeping fuel injectors clean and free from harmful deposits is a critical part of equipment maintenance. Poor quality diesel fuel can cause engine injector deposit buildup that leads to poor fuel economy and engine performance, and expensive repairs or injector replacement that cause unnecessary downtime.

Unfortunately deposits are a common problem in diesel engines. In a recent survey on, 26% of respondents that have experienced performance issues with their equipment identified fuel injector repair and replacement as their number one performance issue.

Two Types of Diesel Engine Deposits

Today’s engines are complex pieces of engineering, and are designed to operate best at specific fuel flows and spray patterns.

Nozzle coking deposits clog the tiny nozzle openings on the outside of a fuel injector. The clogging action negatively impacts fuel flow and the spray pattern of fuel into the combustion chamber, which robs an engine of power and fuel economy, and results in equipment that sounds and feels rough and unresponsive.

Nozzle coking deposits hamper your equipment from running at its best, but they are not the only type of deposits that can cause issues.

Unlike coking deposits, internal diesel injector deposits (IDID) build up on the inside of the fuel injector. However, they both have a detrimental effect on engine performance.

IDID is prevalent on modern diesel engines that utilize high pressure common rail fuel injection systems, or HPCR.  HPCR injectors are much smaller and precise than injectors on older engines, and are much more susceptible to harm from deposits due to their tight clearances.

IDID form soapy or lacquer type deposits on the inside of fuel injector surfaces such as the needle, needle guide, and control valve. When the deposits get to a particular size they fill tiny gaps between parts and cause a sticking action and a timing delay that results in loss of power and fuel economy, and can lead to expensive injector replacements.

Deposits can be so severe that they can cause injectors to permanently stick closed, stopping all fuel supply and in extreme cases they can open and cause a flood of fuel into the engine that could lead to severe engine damage.

Injecting the wrong amount of fuel also results in more black smoke and particulate matter from incomplete combustion, which clogs up key components such as diesel particulate filters, and results in higher maintenance, down time, and even more fuel usage to burn off the particulates.


How to Remove Deposits and Prevent Future Buildup

Deposit control additives in quality diesel fuel, and properly formulated bottled additives, can remove existing nozzle coking deposits and IDID, and can also keep injectors free of deposits with regular use.

Deposit control additives work by clinging to the deposits and removing them from the metal surfaces. With continual use, they also attach themselves to metal surfaces to prevent deposits from building up.

Ask your fuel supplier if their diesel fuel incorporates deposit control additive solutions that cover both types of injector deposits. For situations where a premium fuel is not available, or performance issues are severe, one tank clean up options are available in bottles to ensure recovery of critical performance attributes.

Using a quality deposit control additive will ensure that your engine continues to run at its full power output and achieves optimal fuel economy, while preventing costly maintenance and downtime.