In the drive for greater fuel efficiency and reduced emissions, fuel injectors have become more susceptible to a wider spectrum of diesel deposits. Here we learn more about what’s being done to formulate against them.

Diesel fuel injectors have always been prone to injector coking which constricts the fuel spray channels, restricts fuel flow and, hence, engine power. Traditional diesel control additives (DCA) were primarily focused on overcoming this issue.

Concerns have been building with regards to the susceptibility of the latest fuel injection equipment technology towards high levels of deposit formation in the presence of unstable biodiesel blendstocks, or even trace metal contamination of fuel. Build-up of carbonaceous deposits on these high tolerance injectors can result in loss of engine power, reduced fuel efficiency, increased regulated emissions beyond the designated limits, as well as potentially expensive repairs for the end user.

Original equipment manufacturers (OEM) and injector manufacturers have also expressed concerns regarding internal injector deposits over the last few years. Internal injector deposits may be found on the inside of the body, needle or piston of the injector. They can cause sticking, resulting in vehicle performance problems such as power loss and poor drivability. In some cases, excess power may be observed due to the needle being stuck open.

A new industry test, the CEC F-98-08 Peugeot DW10B injector coking test, confirmed that older DCA do not seem to be very effective in preventing deposits formed from fuel containing trace zinc or pro-fouling biodiesels in the new fuel injection systems.

This finding led to the requirement for new generation, higher performance additives needing to be more effective at preventing this wider spectrum of diesel deposits in both the new engines and the older technologies that preceded them.

If you would like additional information on multi-functional fuel additives, please click below to read the first two articles in this series: