Help to Identify

[5bzhive]

Does anyone recognize either one of these as a thermotime sensor? I am trying to trouble shoot my cold start circuit and I am not sure if I have thermotime sensor.

Thanks

Glen

[black gold man]

Motorsport! Thermo Time Switch, 75-83 280Z-280ZX Non Turbo - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

Motorsport! Cylinder Head Temperature Sensor, 80-83 280ZX - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

Motorsport! Water Temperature Sensor, 75-79 280Z-280ZX - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

[Zed Head]

The top one looks closest but still doesn't look like the thermotime switch (not sensor). It looks more like the CHTS, which BGM linked to. I have both, the thermotime switch is squared off and one piece, while the CHTS has the tapered tip and is two piece. You shouldn't have a CHTS unless you have a ZX engine.

The thermotime switch will measure ~60 ohms through the two pins when cold. When it's hot it will open up.

[5bzhive]

I have a zx engine. P79 head on a F54 block. the sensor with the plug was on the Passenger side on the rear portion of the head so I guess it will be the CHTS. the other was in the thermostat housing with no wires running to it. (obviously since the wires are mostly gone). The only other sensor in the thermostat housing is the engine temp sensor and then there is a plug in another hole.

[Zed Head]

Many people remove the CSV parts. I've removed mine, the switch and the valve both. It's kind of a luxury for a super quick start. Unless it's really really cold out it barely makes a difference.

Are you having problems or just getting things back together?

[5bzhive]

I am trying to get it close to a daily driver. I don't think a FI car should be cranked more than a few seconds before it starts. After this is the cold idle. Just my OCD I guess.

[Zed Head]

So it starts now, but takes too long...

If you end up in the wrecking yard looking for a switch, the easy way to tell is the size of the flats (the part you put the wrench on). Look at BGM's links and you'll notice how long the flats are on the thermotime switch, compared to the others.

The other switch in switch in your picture is for the second magnetic pickup circuit in the earlier 280Z distributors. The wire always breaks off of them.

[5bzhive]

So without the thermotime switch can I make the cold start injector active while it is turned to start or just crank it until it starts without the injector's help? I guess my concern is it will flood out if the injector is active when the engine is warm. I will try to find a used one locally but even my OCD is not worth 75 bucks.