Fountain Valley Mayor Fred Voss, convicted last month of soliciting a prostitute, stepped down from the post but will continue to serve as a councilman. “I do not expect that this action will propitiate the more righteous among us,” Voss said, reading from a statement, “but I am not doing it for them; I am doing it because I believe it is in the best interests of my friends, my fellow council members and the city. . . .” About 20 citizens who attended a press conference called by Voss said they were disappointed he did not also resign from the City Council and vowed to continue a recall effort. Voss, a divorced father of two sons and telephone systems manager for the County of Orange, was arrested Jan. 30 for soliciting sex from an undercover policewoman posing as a prostitute. He was among 16 men arrested during an ongoing police effort to rid Harbor Boulevard of prostitution. Voss pleaded no contest and was fined $300.