WARNING: This page is about a different car, the 2008 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.
Attach timing light to loop wire as shown.
Fig 1: Identifying Timing Light And Loop Wire
Courtesy of NISSAN MOTOR CO., U.S.A.
Check ignition timing.
Fig 2: Identifying Ignition Timing And Timing Indicator