Hello, I have 1980 non-turbo 280zx w/ a rebuilt engine. My car is running rich (black sooty spark plugs) I want to test my CHTS but it is not locate per FSM by the #5 spark plug or on the Thermostat housing. The Thermostat Housing has (3) sensor:
1) Thermotime switch (2 wire injector type plug conector)
2) Temperature switch -below Thermotime switch (Bullet type connection - single wire)
3) (not sure) Temperature sender - left of thermotime switch (single green wire approx. 2" long sticky out connects to bullet)

Could someone tell me what are my number 2 & 3 sensors are for & where might my CHTS will be located.

Thanks

 

What cylinder head do you have? (It's not a P79 if there's no CHTS port).
Who rebuilt the engine and when did the problem start?

Looks to me that someone used either the wrong cylinder head or wrong thermostat housing. Do you have a disconnected plug somewhere???

 

N47 head no CHTS

 

Ok, Looks like I have a L28 engine block w/ a N47 cylinder head. Could the CHTS be located somewhere else?

 

You don't have one....
download the Factory Service Manual from

http://www.xenons130.com/reference.html

 

I've downloaded the FSM and it shows a CHTS. It appears I have a 79 block but a 1980 thermostat housing (See pics above). The thing is I cannot seem to find the wires for the CHTS.

 

The CHTS wiring comes off of the EFI harness running at the firewall by the battery (loom that goes under the hood latch). If it's not there, then I'd assume whoever did the swap used the EFI for the head, and there should be a plug at the thermostat housing harness.