This is the 3rd engine I have made from LEGO. It is LDV-3. I finally found the pictures I lost.
It is a 2 cylinder engine, powered by a 9v motor from the train speed regulator. Powers a nonfunctional generator. The main function of the engine is the NXT computer.
When the touch sensor is pressed it moves the speed regulator knob a little bit and randomly my go back to start position causing the sound sensor to not pick up the engine sound, making a red light and warning sound comes on.
If it runs, the knob on side of the engine controls the RPM until you turn it off.