Passage of a beam of foil-excited He+ ions through a small electric field induced quasiperiodic fluctuations in the intensity of the light emitted from levels n=7,8,9,and10. Both He3 and He4 beams were used. Only one foil was needed, in contrast to the double-foil arrangement reported necessary for hydrogen. The observations are discussed in terms of Stark-induced interference of the fine-structure levels of He ii, but discrepancies between the data and the calculations are large.