The engine doesn't have to be running to move the servos, however, the batteries in both the transmitter and receiver should be charged. You should make sure both the transmitter and receiver are on the same frequency, that the batteries in both the transmitter and receiver are charged, and then you can always lift the front wheels off the ground and trying turning them with the radio. Either way, the throttle servo should still move so it seems like you may have a "power" problem.