The fuel injection systems used in modern diesel engines are much more complex than those used in older vehicles. The higher pressures and elevated temperatures common to electronically controlled common rail direct injection systems (CRDI) combined with the growing use of biodiesel contribute to an increased level of injector deposit issues. These new types of fuel injectors (US2007, US2010 — Euro-5, Euro-6) have nozzle tip holes which are much smaller and more precisely formed than older injectors. These new injectors also have much tighter internal clearances than older injectors making them more susceptible to internal diesel injector deposits (IDID). Nozzle fouling deposits can occur in the nozzle spray holes as well as on the exterior tips of the nozzles. These injector deposits result in reduced fuel flow rate and improper spray patterns which contribute to loss of power, increased emissions and reduced fuel economy.