lespaul166

So I had my car up on the lift the other day and noticed that there are 2 wires coming off a sensor or something at the very bottom of the radiator. Both wires have been broke off. Does anyone know what these go to, and could it affect my idle?

Cameras arsed on my phone so no picks but it seems to be the only wires going to the bottom of the radiator.

DC5Daniel

iTrader: (10)

If it’s a stock ECU, yes, it will effect idle. It was a water thermo switch (there is a total of 4 water sensors and switches IIRC).

lespaul166

I figured as much almost looks like it’s non serviceable? I see no connectors anywher, just some wires broken right off at the sensor.

DC5Daniel

iTrader: (10)

See long discussion with some misinformation before arriving at the correct answer. Yes, the switch does impact startup/idle. However, the less stock your car is the less it’s going to matter.

https://www.rx7club.com/2nd-generati...-106356/page2/

Also, the switch uses bullet connectors, they’re probably still on your sensor. It is removable.

lespaul166

Stock ECU. Really the only engine mods right now. are a header back road race system. It’s had a funny squirrely idle and miss that gets worse as it heats up. I’m not throwing any of my eggs in this basket, but I know it’s gotta be fixed anyways. And if it cleans the idle up 5% I’ll be happy lol

85TIIDEVIL

iTrader: (2)

So is this the same sensor that is on the back of the water pump....??? I have two sensors on the back of water pump. One has a plug w an injector like clip holding it in place and another below it that looks just like this w both wires broken right at the sensor.

DC5Daniel

iTrader: (10)

The sensor (not switch) that you’re referencing with the EV1 connector is the water thermo sensor, which reports coolant temp to the ECU.
The other is the a water thermo switch, which is only present on engines mated with an automatic transmission. I do not believe it serves to the same purpose as the water temp switch at the bottom of the radiator.

Also let's not forget the water thermo switch in the top of the thermostat neck on models which had an electric fan on the AC condenser, and the water temp sender under the oil filter which reports to the gauge in the cluster.

This is the only thread I know of which shows/discusses the switch I believe you're referring to:
https://www.rx7club.com/2nd-generati...switch-448798/

DR_Knight

iTrader: (23)

Recommend replacing the water temperature sensor for the ecu that’s on the back of the water pump housing if you’re having the idle degrade as temperature increases.

It controls the fuel map, adjusting for engine temperature.

you can test it with an ohmmeter too see if it’s stuck at a certain resistance. I do not know acceptable ohm readings.