Timing goes out of whack and engine mgt light illuminates on dash. We have successfully reset this by removing air plumbing from airbox and/or pluggin and unplugging airflow sensor.
It seems to be getting splashes of water from puddles or just a bump and crapping out.
But then next time it will allow me to ford a bonnet-deep bog no worries 
I had suspected a crapped out airflow sensor or poorly sealed airbox. Airbox has been replaced since last outing. A mate told me he was getting very similar symptoms from a VL commodore 3.0L he once had. Turned out to be the 'crank angle sensor' located in the dizzy.
Same guy told me that on his VL upon removing bash plate the ECU has a self-diagnostic switch with LEDS to denote faults corresponding to a fault list from Nissan. Anyone confirm this? I was gunna get it diagnosed by Nissan but fear a waste of money if car's running fine at the time. I can't deliberately make this fault appear.
Airflow sensor quoted $500 from Nissan. Crank angle sensor quoted $200 from efi joint. Too exxy for trial and error.
Any advice? This is doing my head in.
Thanks
Bear
*edit* BTW it's a 92 GQ, TB42e dual fuel.