Have a code p0211 and was wanting to know if someone has had trouble with it.
says throttle actuator stuck?

 

Does your scanner recognize your car as a Crossfire or a M-B SLK 320?
I looked up the code and it came up as a fuel injector trouble.
What's happening with the car?

 

It said Crossfire.the problem is when you start it sometimes it putts and loads up and if you shut it off and restart it a couple of times it stops doing it.but it will do it to when driving.I put a new crank position sensor in,and have a cam one to put in.

 

You could be losing fuel pressure.
Check out this thread: Fuel pressure test
It could be anything from a fuel pump, filter, injectors, or even a bad RCM.
You can get a pressure guage from Harbor Freight, Amazon, etc.. they're not expensive.