I have a 1994 pickup with the 3VZE and it is idling between 1500 and 2000 rpms all the time. It runs fine just idles really high. The check engine light is on for the O2 sensor running lean. Is this cause the idle problem? any suggestions? Also the idle fluctuates when you have foot on the brake. Just up and down.

 

replace coolant sensor not sender. O2 sensor does not run lean, your car is in closed loop due to malfunction coolant sensor making your ecu to tell the motor to run rich!

good luck.

 

It doesnt run rich though. Its running lean. If it was the coolant sensor wouldnt It change where it idles as it warms up?

 

On 3.0 3vze, there are two ports - gauge water temp is sender. ECU uses a sensor.

Yes, Coolant temp sensor once water warms up about 180 degrees it will signal to ecu to reduce rpms.

 

Is there a way to test to make sure thats what it is? So i dont go buy one for nothing.