Temp Sensor reason for running rich?

[dmaxxx]

I have a 2000 x star that I have owned for years. Recently she starting running super rich. I have tested fuel pressure (TBI) and it is a very steady 30psi, so we are good there. I have had what I thought was a bad temp gauge for a year, but now I am thinking it s a bad sensor and maybe it is sending bad signal to ECM?

Does that sound legit? Also, is there just one sensor? Or is there one for the gauge and one for the ecm/switch?

Any help is greatly appreciated. I am in Austin and ride year round.

[AUProStar]

Not sure about a 2000 but in my 95 there is a separate sending unit for the gauge vs the ecm. The sending unit that goes to to the ECM is mounted on the starboard side of the block on my. Ther is a chart to compare resistance readings to determine what water temp the unit is reading.

Could also be a fuel pressure regulator

[AUProStar]

Would also check your MAP sensor.

[amesgardner]

I’m having similar issues and have a bad temp gauge too. Did you resolve your issue?

[MLA]

A temp sensor showing a false cold, will make an engine run rich. Bad MAP or one with the vacuum line off will also.

These engine typically have a single wire temp sender for the gauge and 2 wire sensor for the ecm. Used to be a black wire and yellow wire.