nisscan.com

I'm very curious about the answer posted above by z06warrior. I've never seen such a process mentioned in the FSM for my car. Does it apply only to certain Nissans? What exactly does the process do?

For context, I've got a problem of fast idle on an old Maxima (Oct 2000) with A33 engine. Idle air relearn never completes. I've been wondering whether the throttle position sensor needs recalibrating (the throttle body got cleaned as part of another proceedure, which is when the problem seemed to start). I've followed the manual proceedure in the FSM for recalibrating the thottle, (even wrote a script to get the counts and timing exactly right), but never seems to make any difference. Suspecting an induction leak, the whole induction chain up to and including the plenum has been rebuilt three times. Again, no luck.

I'd like to know whether z06warroir's suggestion is applicable to my case too.

What do your fuel trims show? Parameters: A/F Alpha b1, A/F Alpha b2, A/F Alpha b1 stored, A/F Alpha b2 stored.

If the fuel trims are too far away from 100 the IAVL will fail. The IAVL will also fail if you have any faults, high RPM or high Base Fuel Schedule. z06warroir's suggestion lowers the RPM by disconnecting 2 cylinders. This would lower your BFS as well as there would be less airflow.

Try the "Clear Self Learn" function before doing IAVL. This will reset the fuel trims if they are too far off.