E420 won't start
 

I have searched the site for an answer but found none specific. Here is the problem,

I tried to start the car, it cranked for about 3-4 sec. I thought it didn't start, so turned the key all the way to off position, then realized that it actually had tried to run but I had turned it off in the process. So, very quickly I immediately turned the key all the way back to start position, I think it cranked for a fraction of a second maybe if any. Then now all it does is produce one click under the hood when the key is turned to the start position. Any ideas? I am concerned if I destroyed the starter or it seems like I may have tripped something... Please help

Could be numerous things. Here is my list.

Check your battery voltage by voltmeter.
Check fuel pressure?
If fuel pressure and battery voltage is ok. Then starter is bad.

I hope this helps.

Thanks for the response.
It is the starter. Moral of the story, when restarting the car after an immediate stall give it a second for the engine to completely stop before restarting...