After backers Iso and Marlboro left before the 1974 season, the slightly revised car was renamed the Iso–Marlboro FW, and Frank Williams found that he was underfinanced. At first therefore, a single car (chassis "02") was entered for former Ferrari driver Arturo Merzario, who had replaced Ganley as the team's number one driver. At the season-opening Argentine Grand Prix, the Italian qualified 13th but retired with overheating problems. In Brazil, Merzario qualified ninth but his engine failed before the start and he had to race in the spare car. He retired after 20 laps with a throttle problem.