Jeep: Cherokee Idle, jeep cherokee, air mixture


Question
I have a 1988 Jeep Cherokee with an automatic transmission. I had to replace the radiator, after I was finished it wouldn't idle right, I have to keep my foot on the gas pedal. After I have been driving for about 10 minutes it will idle with out stalling, but is still rough. My gas mileage has gotten really rotten too. I've had it in two shops, but they can't find out what the problem is. I think it is a sensor; I've already replaced the TPS. It has been tuned up.
Thank You
   Scott


Answer
Sounds to me like a temperature sensor, one that controls fuel and air mixture (if your Jeep is fuel injected). Something is feeding your computer false information, making it think the vehicle is at operating temperature when it is not.  I would start by making sure your temperature sensor(s) are hooked up, the contacts clean and the wires in good shape.  If that checks out, you probably have a bad temperature sensor.