The problem you had is one that oil well firefighters also have when running their Diesels around a well blowout. The natural gas will overrev the engine and there's really nothing the governor can do about it. You'd need a CO2 fire extinguisher to kill the engine.

Sorry, can't help you with your problem.

Sholin

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What else, '73 MB 280 SEL (Lt Blue)
Daily driver: '84 190D 2.2 5 spd.