Heavy rain forced the cancellation of Friday's qualifying and the track was still wet on Saturday. Organizers tried to get the track ready but Saturday's race was called off after a two-hour delay.
A persistent wet spot on turn No. 4 was the main cause of the postponement, although crews were working on the track at various places.
Sunday's race is scheduled to start at 11:00 a.m. local time.
Season points leader Helio Castroneves will have pole position for Sunday's race, his third straight top starting position on the 1.5-mile Twin Ring Motegi oval.
New Zealand's Scott Dixon, the winner of the season opener at Homestead-Miami Speedway, took the second spot in the front row. Andretti Green teammates Tony Kanaan and Marco Andretti will share Row 2, and Dan Wheldon and Danica Patrick will start in the third row.
