Intake valve deposits, gasoline engine fuels

Fuel injector and/or intake valve deposits may be present in gasoline engine... 

One additive that has been used for many years is ethanol. However, the use of ethanol in a gasoline combusted in an internal combustion engine is well known to create harmful and imdesirable deposits on the fuel intake valves of the engine. 

Tetraethyllead is the most important additive used in gasoline. It greatly increases the octane number. Antioxidants are used to inhibit gum formation by oxidation and polymerization in storage, and they prevent potential gum-forming substances from depositing in engine fuel lines, carburetor jets, and on intake valves. Military specifications for... 

In gasoline engines, most detergents will prevent deposit formation on carburetors, fuel injectors, and intake valves. Some detergents also possess the ability to remove existing deposits from intake valves and control the formation of deposits within the combustion chamber of an engine. See FIGURE 6-14. 

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