 1979 was his most active year as the CART/USAC split ruptured champ car racing and Weiss competed in the USAC events at Ontario, both Milwaukee races, and Pocono Raceway and the September CART race at Atlanta Motor Speedway.He registered a career-best finish of 7th in the August race at Milwaukee and finished 16th in the 1979 USAC National Championship.Weiss attempted to qualify for his first Indianapolis 500 in 1979 but failed to complete rookie orientation.