Hi, I am currently working on changing the gasket between the head and the thermostat housing on my 1976 280z manual Datusn fuel injected.

My housing has four sensors, see pic below. The top right sensor next to the gauge sensor is the one that the cable broke while I was working on it

I took it off and it dosent seem to be a sensor its just empty inside, do I really need this sensor? Can any one help me in telling me what each sensor is and does?

I dont have an electric fan its just driven by the belt

Also since I am here, can you also tell me where does the back hose does or ends up at?

Thanks Blue, I have seen that picture before

But my housing has a hose where the water temp switch is in you picture, why is my housing sensors arranged diffrently?

All of my sensors are in the front

Are you saying that the sensor next to the temp gauge is the water temp switch? Why is my arrenged diffrently?

Can you tell me what each one does?

Do I need the one next to the temp gauge?

I have searched around but I cant find anything that really tells me anything

Oh and my housing is the one with the red background, the other one is just as a reference

To expound on Blue's notation - it activates another circuit in the ignition module to use the other pickup in the stock 76 Fed model distributor. It advances the timing about six degrees when cold. The purpose is unclear, it might be for raising the idle speed. It's not necessary, but you might notice a low idle speed until the engine fully warms up. If you're distributor or ignition module are not stock, then it's useless.