300TD - doesn't shut off when key is pulled out?
 

Checked out an '84 300TD last night, and when I pulled out the key, the car still ran for a good 15 seconds before it shut down. This happened twice. Any idea on what the cause of this would be?

It REALLY liked the diesel you put in it this time. :D

It has a small vacuum leak. Or the shutoff valve is going. Neither is a big deal, however if shutoff valve is going you will get oil in vac lines. Check for that in brown vac lines if you look at car again.

The best way to test the shut off valve is to pull the vac line that runs directly to it and test it with your Mityvac (a very handy device that no antique MB Do-It-Yourselfer can live without) you can pick one up at Autozone for about 25 bucks.

Anyway, start the engine up, pull the line for the shut off valve, and give it a tug with your mity vac. If the engine shuts right off, you're going to have to start checking your vacuum system for leaks. If the engine stutters out or simply doesn't shut off, then you're going to have to replace ths shut off valve.