Car start and immediately shuts down.

I have just had the same problem, what I found was the Crank sensor was covered with iron filings. Clearly picked up from the flywheel debris. Cleaned up now, but the hex bolt was the devils own job to remove. I ended up bending an old Allen key into shape and using a pair of mole grips to turn the small end of the key to loosen the bolt. Getting to the sensor required a lot of water pipe removal and the unbolting of the oil filter housing and associated water cooler. Happy now the mystery is solved, as this has taken several months and the purchase of a ODBEleven as an ordinary ODB reader did ot show the Crank sensor intermittent fault.