So, if you have a high mileage (unknown but 400k+) om617 and most of the time it shuts off right away with the key, but occasionally it wouldn't shut off right away, and at first it would shut off by itself after 30 seconds or so or when you press the stop lever, but now sometimes you can press the stop lever all the way and it slows down but keeps running, then if you press the stop lever again it will shut off is there any way to fix it? It has no problems probably 95% of the time so there is not really any way to test anything, but does anyone know what could cause that? I can't really work on a diesel beyond stuff like changing fuel filters and stuff that's no different from a gas engine so im not sure if I should try to get rid of it before it gets worse or not.