Coolant Temperature Sensor location

I've been chasing a high idle problem in my 97 Tacoma 4x4 which has the 2.7 liter 4-cylinder. Already had the throttle body cleaned, replaced both the TPS and IACV, as well as confirmed no vacuum leaks but that didn't seem to help. After researching this problem thoroughly I ran across some threads about replacing the Coolant Temp Sensor. The rationale is that this sensor may be tricking the ECU into thinking the engine is not fully warmed up. (BTW the thermostat seems to be good). First off, am I on the right path here? Second, where is this sensor located?

 

Did you adjust the throttle, and if you have it, cruise control cable? There's a specific procedure and a bad cable on either one will cause this. Even a bent bracket that holds the cables. Sticky throttle body butterfly valve too.

 

If the temp sensor failed a CEL would be ON.
Time for a new throttle body or MaxBore

 

As far as I know I reset both cables back to stock position after cleaning the TB, but I will recheck them. Thanks!

 

Well if the wire inside the cable is frayed inside the sheath you won't see it. I'd disconnect both and check for free movement. any tension whatsoever just replace them. Not worth lubing them.Plus disconnecting and starting it will tell you. If the idle is normal after disconnecting both, and trans kickdown if an auto, then its a cable issue.

 

The CEL has been on for years, and I always figured it was emissions related. From what you are saying it sounds like there would be a stored fault if this sensor was bad. I will have it scanned and see if the sensor shows up. I have also been pricing out new TBs, and the truck has 263K miles so it is probably time for a new one anyway.

 

http://www.maxbore.com/

 

The TB's are easy to clean. I did mine on my LC. best to remove it which is time consuming as is recalibrating the TPS. You can test the temp sensor without removing it I believe but if you have a code thats the starting point.

 

Did you check that the IAC butterfly isn't stuck, you have to remove the solenoid from it to see but the shaft should move freely. Also some of the older Toyota's had a separate mechanical idle control valve that had coolant running through it in addition to the electronic one, not sure if yours has it or not but if it does check to make sure the coolant passages aren't plugged.

 

Good suggestion.... was going to take the TB off and check everything again. Will check the IAC to ensure it moves freely.