i have a 1990 na rx7

i have a quick question, is the water thermo sensor on the back of the water pump housing connected with the temp gauge on dash board. my temp guage works perfectly as far as i know. but i was think of changing the sensor due to some startung problems and idle purging.

i ask because looking at my sensor previous owner poorly rewired it.

so i want to know if its working properly since my temp guage works

thank you

 

The thermosensor on the back of the water pump housing is just for the ECU. The temp gauge's sender is on the rear plate under the oil filter.

A bad thermosenor (or a lack of signal form it) will cause the engine to run poorly when it's cold. You can check the signal by measuring its voltage at the ECU. Instructions how are in the FSM Fuel Systems chapter from page F1-78 onwards. Check pin 2E.

What exactly do you mean by "poorly rewired"?

 

i will check the ecu pin then.

it was wired with speaker wire from the sensor to the original wire witch was behind the dynamic chamber under the thermowax.

so i replaced it with better wire and connectors.

 

With a fully hot engine, the pin will read approx a half volt or 0.40v to 0.50 depending how hot is hot.