Has anyone tried hooking up a rheostat or potentiometer in place of the chts? i heard people did this back in the day to richen or lean the mixture up a bit.
-Andrew

 

Yuppers. When I worked at Nissan back in 97-00, the head mechanic did that trick to my car. The CHTS sends an ohm (resistance) signal to the ecu to give the temp value. You can adjust the potentiometer to trick the ecu into thinking the head is still cold, which will enrich the a/f mix. I can't remember off the top of my head what the ohm rating is, but it seems like it's a 10ohm or 100ohm to 1k or 10k... Just look up the specs in the FSM.

 

yes i believe i saw one that was from 1k ohm to 5k ohm according to the graph in the fsm that should work out ok gotta love how most of the sensors in the z are resistor based so easy to trick

 

It's actually a trick you can use on the air temp sensor IIRC to enrichen the mixture as well. It's hardware hacking an old system. If you really want to play with your fuel injection dump the 1970's electronics and install a Mega Squirt ECU then the fun begins

 

Well seeing as nissan canada has DISCONTINED the chts all together and cant seem to get a correct one aftermarket, i may just have some fun with the jetronic system I would love to megasquirt and i am quite capable i just want the car to run ok stock before i spend the dough on megasquirt.

 

The Z31 used the same CHTS. And the 280Z / Early 280ZX used the same sensor in the thermostat housing. I know the parts stores categorize it as a coolant temp sensor ( Duralast/Coolant Temperature Sensor (SU403) | 1980 Nissan/Datsun 280ZX 6 Cylinders H 2.8L FI | AutoZone.com ) Heck, I have a few I could part with myself.

 

Yea i noticed that they call it a coolant temp sensor and what gets me is they show that it comes with a copper washer but we all know its a dry cavity lol.
I was gonna grab this one for the sake of it being original, but the part number on the package is different then the number courtesy nissan lists.
280ZX ENGINE COOLANT TEMP SENSOR 1979-1983 GENUINE NISSAN | eBay

i like the potentiometer idea

-Andrew