Originally posted by vinj
It only happens when you run over a hump or when you're revving in gear (3k RPM) then you let go of the gear and let it go to neutral? Does your car idling divebomb before it settles to the normal idle speed after you rev it to 3-4k rpm then let go?

Unlikely its with the computer box though.

Try to check out this website as well: www.nissanbayan.com
It happens consistently when i run over a hump and occassionally when i rev it to 3-4K.