Has your injector life been dramatically reduced? Are you also seeing increased fuel filter plugging? Are you seeing a very dark substance on your fuel filter media? If the answer to these questions is “Yes” you may have a salt problem.
The North American diesel fuel market has moved from High Sulphur fuel to Ultra Low Sulphur (ULSD) fuel (<15ppm). A result of this change has been the increased failure rate of fuel injectors. And surprisingly the problem is not an electro-mechanical failure but rather a seizure between the needle and the seat.
The seizures are caused by the formation of salt causing “sticking injectors”. More specifically, these are Carboxylic acid salts that are being formed by the combination of Sodium and Corrosion Inhibitors found in modern day ULSD.
The Sodium can come from a variety of sources (refinery salt dryers, storage tank water bottoms, seawater, etc.) The Corrosion Inhibitors, which is primarily dodecenyl succinic acid DDC Acid) and hexadecenyl succinic acid (HDS Acid), comes from pipeline drag reducer, refinery corrosion inhibitors, refinery neutralizing agents, additive packages and other aftermarket products.
These two components combine to form these problematic salts that have very poor solubility in ULSD and are only partially affected by filtration. The high fuel pressures found in the modern day common rail diesel fuel systems, and the close internal tolerances of the fuel injectors, these salts find a home at the junction of the needle and seat.
The only real solution for the end-user is to stabilize their fuel; which is primarily accomplished by “treating” the fuel with an aftermarket additive. Be warned…not all aftermarket additives are created equal. Work with a reputable company that is aware of this problem and has done the research on dealing with this problem.