I've recently installed my freshly rebuilt engine. For the most part, everything is groovy… What a fun car to drive!

I've been having some lumpy idle issues once the engine has been at normal operating temps for about 15 or 20 minutes.

I'd like to eliminate water temperature sensors as a potential cause. My question is which of the two water temp sensors provides data to the ECU? My guess is that the sensor at the back of the engine only feeds the dashboard temp gauge…?

Or are both of 'em involved?

Many thanks for the help!

Cheers,
Tom

 

There are 2 sensors at the back of the water pump housing. Top one with two wires is the ECU input, the bottom 1-wire is the fan switch. Just below the oil filter is the 1-wire sensor for the gauge on the dash.

Dale

 

Perfect! Thanks for the clear info!

Tom

 

Just curious but once you go power fc the one wire fan switch becomes useless doesn't it? Doesn't the power fc take control of the fans?

 

Nope. The ECU controls one fan input, the thermosensor controls one fan input, and the AC controls one fan input.

Dale

 

Hello and sorry for dragging up an old thread... I am trying to get my temperature and oil pressure gauges working. Is anyone willing to help me figure out which wire it is that goes to the water sensor and what color it is? I would like to figure out where the oil one is as well and what color its is too.

Thanks in advance!!!

Jesse

 

Could I tap into one of the 3 sensors for an aftermarket gauge? I'm currently running it in the hose that is supposed to run through the throttle body in a brass adapter I made, it looks like a DIY job under the UIM to say the least.

 

As long as the existing Oem sensor has the same range of resistance for temperature as your aftermarket sensor, you can tap the stock sensor. Otherwise, I have mine in a brass T in the throttle body line as well. Works fine.

Matt

 

Is there any chance of input on my question above?

 

https://www.rx7club.com/3rd-generati...ctures-892648/

https://www.rx7club.com/3rd-generati...t-wire-915592/

look at those threads and the location of those wires is shown

 

Thanks cr-rex!