your engine temp sensor in the airbox may be faulty and needs replaced.
These things if bad, will tell the engine wrong tempurature and the ECU will
then try to either advance the timing or retard it depending on those
readings. Another thing at fault may be the crank angle sensor that also
control timing. It may not be advancing the timing or retarding properly,
but the Consult computer should pick these readings and send a fault code
linking the problem.
Did you have Nissan perform the consult on the car? Do this
if not.
Chris 92 classic