I had a problem in that I turned the gas and fuel off and tried to vent the engine with the starter motor. However, I had the ignition left on. As the temp was still high, every time I tried to vent the engine the ECU thought I was trying to start and ramped the fuel that was left in the line aft of the fuel tap. This caused repeated fires until the ignition was disconnected.

I'm not sure how the autostart one works, but if you can turn off the ignition all the better. Even better than that would be if you could disconnect the fuel line at the engine too but it's a bit tricky with the L39.