Q&A

 Master

This is going to require performing some tests and diagnosis to determine the problem. Better take this to have it diagnosed if you cannot perform these tests yourself.
http://repairpal.com/moreno-valley-auto-repair

It can be your key not syncing. Can you try another key?

very common problem on the Ml 320 : Crank sensor located on top of flywheel- driver side- cost of replacement: < $250

mine had this problem and it was the timing

pls. check your fuel pressure if its no pressure then you have problem with your fuel pump or your fuel filter i think this most common problem for ml 320

It could be your immobilizer, remote control key or the control unit.
Try starting the car with your spare key.
Muzza