Diesel Pathfinder Idle Issues When Cold
 

I have a 2006 R51 Diesel Pathfinder.

When I start it for the first time each day or when it has sat for a while and cooled down, it won't idle, and unless I work the accelerator will stall and then is very difficult to start. When running it is blowing black sticky gunk out the exhaust.

If I keep the revs above 1,000 it keeps running, is responsive, and eventually warms up and will idle.

I have checked for air leaking into the system - sprayed petrol (gasoline) all over the motor - no reaction until sprayed into the air cleaner element.

I have replaced the cam sensor and mass air flow sensor as they both indicated on the diagnostic computer.

Once warmed up, I have performance, power, idle and ecconomy. If I stop for a short spell, it starts as normal and idels when I get back in.

I am stumped and would love some advice please.