While I agree with what MBCO and Senecat say, in my case no codes were or are thrown. My car starts fine 95% of the time but if I add gasoline, either a fill up or just a few gallons, it won't start normally. Sometimes it will start and then die, other times crank but no start. The only way it will start is to have one foot on brake and other on gas, press gas down at least half way, sometimes more, and it will eventually start. It will run rough, need to feather the gas, but then will be fine until next fuel stop with a dozen engine stops and starts.
When my car would shut off after it started it was like the engine was still running. No indicators would change on display, I would need to push button to 'turn off' the car before I could try to start again.
The question for 06SL500AMG: how does it run when it does start, and how long?