Okay so I've been having some run-on issues with my 1982 240D. I found out something the other day. run-on does not happen when I lock the doors prior to shutting the car off. run-on does happen when I don't lock the doors. does this help diagnose where my issue is?

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1973 280 - Sold
1980 300SD - Sold
1982 240D - Stolen
1988 300E - Sold
1989 260E - Sold
1989 560SEL
1994 E420 - Sold
1997 E420
2005 CL500