[@LokiLeo789]

EMP implies it's suppose to be an electrical pulse meant to short out electronics. Which might have been useful against technologies from the fifties, but even now most of our tech, even stuff like cellphones and laptops, are properly protected enough that an EMP won't fry them. You'd need nuclear warhead level stuff, and the Machinas are well past our current technology level that those sort of rudimentary tactics wouldn't work as well as you'd think. 

Also Graf uses machines and technology, but he's more of a ghost in the machine than a true AI. Even a direct electrical pulse would, at best, shut down most of his weapons, but he'd still move perfectly fine. So yo dood would be in for a nasty surprise if he expected an EMP to stop this tin can colossus.