Coolant temperature sensor?

Hi,

One of the things the coolant temperature sensor signal is used for is the air/fuel mixture. If the gauge is correct, chances are it is working properly. However, there could be a wiring issue, corrosion, or a poor connection causing issues.

The best thing to do is check the ECT signal using a live data scan tool. That will tell you the temperature signal the ECM is receiving.

Keep in mind, a rich fuel mixture can be caused by high fuel pressure, an oxygen sensor issue, and so on.

Let me know if you retrieved any diagnostic trouble codes and what they are. If you haven't already, it would be a good idea to check the fuel pressure to make sure the regulator is working properly. Here is a link that shows in general how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Pic 1 below shows the directions specific to this vehicle from my manual. Additionally, it provides the manufacturer's fuel pressure specifications.

Pic 2 is a description of what the coolant temperature sensor is responsible for and what it controls.

If you have a live data scan tool, check the sensor's signal. Also, let me know what the short-term fuel trims are.

Take care,

Joe

See pics below.