The series of stoppages left it impossible to draw any serious conclusions about relative pace, although it remains clear that McLaren are the team to beat.
Frenchman Isack Hadjar, though, continued to impress for Racing Bulls with third fastest time on his first visit to Suzuka, considered one of the most demanding circuits on the calendar.
His team-mate Liam Lawson, who was demoted from the Red Bull team after just two races before this event, was fifth fastest behind Lewis Hamilton’s Ferrari.
Mercedes’ George Russell was sixth fastest, from the second Ferrari of Charles Leclerc.
Max Verstappen was eighth, complaining of understeer in his Red Bull, with Pierre Gasly’s Alpine and the Williams of Carlos Sainz completing the top 10.
Yuki Tsunoda impressed in the first session, topped by Norris, after his move up to Red Bull in place of Lawson, with sixth fastest time just 0.107 seconds slower than team-mate Verstappen.
The Japanese was only 18th in the second session, not completing a representative lap on the soft tyres.