OK- I know I must have a vacuum leak somewhere, and at some point I'll need to chase it down, but here's the weird thing. When it's 60+ degrees outside and I shut off the key, our 190d keeps running for about 20 secs before shutting down. Now that it's below 50 degrees here- when I shut off the key it shuts down immediately. This is regardless of what operating temp it is.... What's going on? Does anyone have any idea what might be causing it to run-on when warm, but shut down when it's cold? Thanks in advance- J

Sounds like a thermal expansion or thermal shrinkage problem of course. I guess the cheapest thing to do first is to buy or borrow a vacuum testing device. Mityvac comes to mind. Then check everywhere and eliminate any vacuum leaks you find first. This might solve your problem. You could monitor your vacuum I suppose and spray connections etc with freeze spray available at electronic stores if the first approach did not find it. That would instantly boost vacuum when the trouble spot is sprayed as causes instant thermal change. Could even be the shut off valve itself or a marginal vacuum pump. The tester should find it. I am not familiar with the 190d at all by the way.

Hmm- worth a shot, I'll try and fiddle with it this weekend. Hoping it's something obvious and under the hood! If it's behind the dash... I don't want to think about it.