if you can put it on gas you can!!! or, and this works but i'm not sure of the success youll have with an efi you can just introduce propane in to the intake, there is a problem of getting it to spark. i suppose you could build a test system but if your going to that hassle you might aswell chuck it in the car.
does the efi have distributer? if it does then all you need is power in the right places and use propane. it should be fine just to run it for half a minute!!