Fuel Injection Service / Fuel Induction Service?

[Lux]

The fuel injector service is performed by disabling the fuel supply and pressurising a caustic cleaning solution directly into the fuel rail for the engine to run on. It will run on it for 20 to 30 minutes.

Its purpose is not to clean the injectors -- that is a secondary effect of the service -- but to clean the intake and exhaust ports of the cylinder head and, to a lesser extent, the combustion chamber. Carbon deposits can form on the valves over a period of time; fuel quality, oil consumption, combustion temperature, and foreign matter are contributing factors to carbon deposits. Engines that are not driven at high rev, high temperature periodically are more likely to collect the valve deposits. Revving the hard from time to time can burn off the deposits if they are not severely baked on. There are technical service bulletins for Chrysler, Audi, and Volkswagen cars (among others) with direct injection engines that specify high revs to help burn them off. Valve temperatures fluctuate constantly because they will cool when retracted into the valve seat... the change in temperature is what promotes the collection of loose particles.

The effectiveness of the service is dependent on the quality of the cleaning agent and the technician's competence. For best results by this method, you need industrial-strength chemicals that are not publicly available.

For a DIY equivalent service, you can use stove cleaner on the valves with the manifolds removed from the cylinder head.