As i said just shoot a little in air cleaner with it running and see if she perks up. As far as inputs i have a few and knowledge i have very little but i seem to keep a fleet of 50 these things going LOL. One other thing to do is just for giggles, remove the main lpg injector after the unit has died from fuel being shut off at tank. get some good ole penetrating oil( the thin wd stuff) and spray the injector while turning over the engine. The injector will pulse and you should see all kinds of small black particles coming out. This will be a sign that the plunger in injector is probably galled and injector is scrap.