Purchased a 2000 C230 a few months back because I liked the car and the price was REALLY right.  It's spent 95% of it's time sitting, only being driven occasionally.  The wife hopped in it yesterday to run a few errands and found the battery dead.  No problem I thought, popped in a new battery, started it up, seemed to run fine, shut it down and walked away.  She decided to use it again today but before she got even a block away the car started surging badly so she drove it back and told me of the problem.  Figuring it probably had something to do with replacing the dead battery I changed I asked a Mercedes mechanic who said turn the ignition switch on for 5 minutes, turn the switch off then start the car. This would readapt the throttle module.  Well that didn't work.  Any suggestions?