The "run on" problem has been discussed before.
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Board=2&Number=88201&Searchpage=1&Main=13310&Words=%26quot%3Bengine+will+continue+to+run%26quot%3B&topic=0&Search=true#Post88201

Hopefully this will help