engine is idling at 2000rpm. this start to climb slowly. will not idle at proper

-48degrees reading is not a right value(unless you are at North Pole) . You have to go figure out what causing this reading first.At this reading engine will run rich .

Coolant temperature reading is not right unless that is the correct ambient air temperature.If that is the reading you have to test the coolant or air temp sensor at the computer to see what is actually going on. My guess would be a vacuum leak. Do you have any vacuum leaks around the intake manifold, it's gaskets or hoses attaching to the intake manifold? There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online