Let me start by saying I am in no way a mechanic but I know enough to get myself in trouble lol.

I have a 2000 Komatsu FG25ST-12 with a propane Nissan engine. I had issues with the machine starting but immediately shutting off. I had my mechanic come onsite for a brief look and he suggested a vacuum issue and to change the LPG converter. I changed the converter module as well as the lockoff module. Hooked everything back up and still same issue. If I disconnect the vacuum hose on the converter and suck on it while turning over it fires right up, then shuts off again as soon as I stop.

Obviously I have a vacuum issue but I'm not certain where to go from here and am trying to minimize my mechanic call out bills. :)

Thanks in advance for any feedback/help.