Yes, there is a special tool to pull the plug wires. It's not expensive, but you need one.
see 103-0037
http://www.peachparts.com/diy/mb_tools/mb_tools.php?page=22
As far as starting problems, the OVP, OverVoltage Protection relay, A silver can with a red top and a fuse or two, needs to be checked. Vibration causes the solder joints to break and there could be a bad fuse. Open the can and resolder the connections.
The large solder joints in the fuel pump relay can also crack and open. Resolder them.
Perform searches on OVP and fuel pump relay and you'll see lots of entries. Cracked solder joints in European cars are almost a given.
You'll need to check the 'duty cycle', so do a search on that too.