  GW Vir variables are the pulsating members in the spectroscopic class of PG
1159 stars. In order to understand the characteristic differences between
pulsating and non-pulsating PG 1159 stars, we analyse FUSE spectra of eleven
objects, of which six are pulsating, by means of state-of-the-art NLTE model
atmospheres. The numerous metal lines in the FUV spectra of these stars allow a
precise determination of the photospheric parameters. We present here
preliminary results of our analysis.
