im not seeing a mass aiflow sensor listed on JDHT but it would make sense that there would be one behind each airbox

 

that dose make sense two sensors and right where the air flow would be but the idle screw where is that ?

 

Good work.

Now that you have it running make sure your coolant is up to spec and all connections are tight.

You should have the 6 litre engine in your X81. One of the best V12's ever made IMO but don't overheat them.

 

Pardon the "johnny come lately" chime-in from me, and I may be way off, but, I have been told that the air mass meter/sensor are sensitive to internal contact of any kind.