I have a 1997 Ranger , 2.3 , 5 speed , check engine light is on , code says it is the coolant temp sensor , replaced it and now the truck starts fine , runs great , but will not start again untill it cools of , even if it just runs for a few seconds , the check engine light is still on and the water temp gauge does not work now either . Tried switching to the old sensor but still have the same issues . Truck runs great and gets good gas milage , just does not want to start unless it is cold . ANY IDEAS ??

 

If the sensor is brass, do not put any teflon tape on it, it could block the electrical signal.