It is the spray from the Ford fuel injector that introduces the fuel to the combustion chamber. There is a single fuel injector for each cylinder on your Ford car or truck. If this fuel system component is not cleaned at regular intervals, it will become clogged and an insufficient amount of fuel will be supplied to the combustion chamber. The typical way for a Ford owner to clean their fuel injectors is to place an injector additive to their fuel tank about every 5 to 10 fill ups. This frequency is determined by the potential level of contaminants in your fuel supply and the frequency of the fuel filter being replaced on your vehicle. It is also possible to partially clean the fuel injectors manually. This requires the Ford fuel injectors to be physically pulled from the engine and soaked in a solvent. The use of a tooth brush can also be used to help remove some of the build up in the exterior of the injector. This procedure will not be able to clean the inner portion of the injector, but any build up on the outside of it can be removed. When this procedure is completed and the fuel injectors are placed back in the engine their interior should still be cleaned. This again is with the special additive being added to the fuel tank. This will clean the inner components of all the residue that will be accumulated over all the time your injectors have been used. If your Ford engine does not have a steady spray of fuel into the combustion chambers, the performance and horsepower it can produce will be negatively affected until the situation is corrected.