2009 3l Nissan Patrol Y61 Ti, blowing black smoke!

[Sam144]

Not sure if this is the right place or not...... New to this forum.

My Nissan Patrol randomly drained it's fuel lines one night ( no holes or leaks) then is started blowing heaps of black smoke. After discussions with a mechanic, We changed the sensor on the air filter bit, no change. Took it to a fuel injection place in town and they tested it with a Valve Block afte smoking out there workshop........., apparently it worked and reduced the smoke significantly, but due to the legalities they could not leave it in. We have bought the car home and made a valve block as per the gasket which is on the intake, test drove it and it still blows excessive smoke...... Any ideas what else to try? Don't think my neighbourhood enjoys being smoked out.....