The growth of the distortion of the director in an external field, and its relaxation on removal of the field are studied for nematic solutions of the rod-like poly(1,4-phenylene-2,6-benzobisthiazole), PBZT, over a range of concentration, polymer molecular weight and temperature. The twist viscosity and the order parameter are more weakly dependent on concentration than predicted for charged rod-like chains. This behaviour implies a short-range translational order in a direction orthogonal to the chain axis, induced by electrostatic interactions among the polycations on protonated PBZT. The relaxation gives a normal temperature dependence for the splay curvature elasticity, but that for the twist curvature is unexpectedly strong. This behaviour is interpreted as a weakening of the surface anchoring with increased temperature.