Structure and counterion diffusional mobility in simple models of solvent-free linear chain ionic heteropolymers has been investigated using molecular dynamics computer simulation. A generic coarse grain Kramers model was used in which a fraction f of charged monomers are distributed uniformly along the chains. Only excluded volume and Coulomb interactions are considered. Four compositions were studied with f=0.17, 0.25, 0.33, and 0.5. Computed partial pair distribution functions show that for all compositions the short range structure is consistent with essentially complete condensation of the counterions over the whole temperature range studied. For low values of f two glass transitions can be distinguished-a higher one, T-g', which is invariant with composition and is associated with ionic clustering, and a lower T-g" associated with neutral regions of the material. Partial structure factors confirm that the intermediate range structure is increasingly heterogeneous as the fraction of charged chain monomers is decreased and the associated order persists at temperatures up to at least 3.5T(g)'. At greater than similar to1.7T(g)' the counterion mobility is clearly decoupled from the chain motions in all samples. Diffusion coefficients do not show a strong dependence on charge fraction in the range studied although there is evidence from plots of mean squared displacements against time that for intermediate compositions, e.g., f=0.33, large amplitude motions of neutral monomers may promote an increased mobility of counterions in the approach to T-g'.