Police say he struck Sunday on Kester Avenue in Van Nuys.
A woman says the suspect pulled up in a black sedan and asked for directions. When she ignored him, he grabbed her, threw her down, choked and sexually assaulted her. Then he drove off.
Anyone with information is urged to call the LAPD Van Nuys Detective Sexual Assault Unit at (818) 374-0040, or (818) 374-9500.