I have a 1980 300D, and it doesn't turn off by key, and now the stop switch under the hood doesn't work either. I tried popping off the linkage attached to the injector pump and yanking on it, and that didn't work either. Disconnecting the battery doesn't work. The only way I got it to turn off was by disconnecting the fuel supply line at the clear filter, and then accelerating a little to hurry up the shutdown time. But it still took a good 10 minutes to turn off.
My problem is that I'm in desperate need of a vacuum pump rebuild, but it makes me wonder. Why isn't it turning off with the stop switch/linkage? Is that still somehow because of the vacuum pump? I'm going to order a vac pump rebuild kit (thanks to info from someone on this forum), but until then, is there another way to shut off the engine? I don't think applying vacuum to the vacuum unit on the injection pump works either. I'd appreciate any information anyone can provide, no matter how small, etc.
My problem is that I'm in desperate need of a vacuum pump rebuild, but it makes me wonder. Why isn't it turning off with the stop switch/linkage? Is that still somehow because of the vacuum pump? I'm going to order a vac pump rebuild kit (thanks to info from someone on this forum), but until then, is there another way to shut off the engine? I don't think applying vacuum to the vacuum unit on the injection pump works either. I'd appreciate any information anyone can provide, no matter how small, etc.