start car without key?

Hi i just need a bit of help, ive brought the black Elise that was crashed at the front with the Audi engine in but didn’t get the key. Im taking the engine out of the car to fit it in another Elise/Exige but wanted to make sure it all runs ok before i take it out. i can by pass the ignition but i dont know what the immobilser cuts off? (fuel pump, crank sensor etc) What do i need to bypass to get her running again?