Nearly always on MBs and BMWs, jump starting will blow the OVP fuse, causing the hard starting and needing to put foot to the floor that you describe. I'm not entirely sure if your car has an OVP relay though.

later

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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg