<p>An oil activated fuel injector includes a control valve body with end cap solenoids and a slidably mounted spool. A minimized contact surface area exists between the spool and one of the first and second solenoid coils providing a minimized ratio of surface area versus boundary line of a contact surface to prevent a change in latching effects. The minimized surface may be on the end of the spool or one or both of the end caps. The minimized surface area may be a raised portion of different dimensions. <IMAGE></p>