I am trying to wire up my temperature sensor to the ECU. This is a D16Y7 motor in an '89 Civic DX body, with the '89 DPFI and ECU.

The B motor had the temperature sensor in the back of the block. The D16Y7 has a sensor at the thermostat housing. I've read on here that simply extending the wires to the thermostat housing is enough to get things working properly.

Has anyone here done this? Is that really all there is to it?

I've been driving this car for a year with the temperature sensor connector unplugged and dangling. But I'm hoping the engine might run better with the temp sensor attached properly.

 

that sensor is actually the switch that turns on the cooling fan - yes, you just need to extend the wires for the switch on the back of the block and put a 2-wire connector on it so that you can plug it into the switch on the thermostat housing

 

Do you know if that sensor is only for the cooling fan switch? Or does it inform the ECU? I don't know if OBD0 uses a coolant temp.

I figured out that if I short the two sensor wires together, my radiator fan comes on. I've heard different things - I've been told that without the coolant temp sensor hooked up the cold start injector will be dumping too much fuel into the mix.

But I don't think there is a cold start injector in the DPFI setup. Is there?

 

the one on the thermostat housing is only the coolant fan switch - the coolant temp sensor for the ECU is on the end of the head below the distributor - has a 2-wire connector with red with white stripe and green with white stripe wires - the coolant temp sensor for the temp gauge is also on the end of the head and has a 1-wire connector with yellow with green stripe wire

 

Thank you for the detailed info. I checked and found the sensor and the sender, both hooked up. This is great, that's what I wanted to check.