I had starting problems with the 4/4 late 2010.
It was a bad earth.
I by-passed the negative circuit via chassis and lead to the starter mounting bolt using a jump lead from battery negative to the mounting bolt.
Car started immediately every time indicating a failure in the circuit somewhere.
I tested the circuit between various points but in the end I cleaned up every joint/bolt connection etc in the negative circuit, cleaning contacts and vaseline to protect. Never a problem since.
