On the back of a block

On the back of a B18A(90integra) there are 3 sensors. One of them has green connector with 2 wires. Second sensor has one wire in a bell like shape housing. Third sensor is like the second but it is bigger and it has 2 wires. I'd like to know what are those sensors. Thanks.:silly2:

possibilities are knock sensor,engine temp. thats all I can think of right now but if you got a manual that would be a good place to start