Talk:fire up

I'm betting that this idiom originally comes from steam engines, probably rail. You literally have to fire up the firebox to get the boilers started producing steam so that the engine can start to operate, so firing up is the initial procedure and everything else follows from that. Any thoughts? Any evidence one way or another?
 * Seems reasonable, however the OED says "Apparently recorded earlier in English than the literal sense". SemperBlotto (talk) 15:04, 20 July 2019 (UTC)