A plug connector for connecting to an electric connection of a fuel injector of an internal combustion engine can comprise a rail extending in a longitudinal direction and at least one insulating element arranged in a linearly movable manner in the longitudinal direction relative to the rail, wherein the at least one insulating element protrudes out of the rail in a transverse direction. In some embodiments, the at least one insulating element comprises means for electrically connecting to the electric connection of the fuel injector in an oil-tight and releasable manner on a side facing away from the rail in the transverse direction. In some embodiments, the rail comprises a guide extending in the longitudinal direction configured to guide the at least one insulating element relative to the rail in the longitudinal direction and hold the same in a formfitting manner in the transverse direction relative to the rail.