ROUGH IDLE AND STALL WHEN WEATHER IS WARM.

Check for broken breather hose from valve cover and follow it under the intake. You may also have a ruptured diaphragm crankcase ventilation valve (vac leak), bolted under intake manifold.

Check the coolant temp. sensor (It controls warm up RPM, open loop ECU mode) And change the fuel filter every 20,000 miles to prevent water in filter from freezing ( fuel starvation).

sounds as though the fuel system is set for a differant climate then your living in take it to the shop and get it set for your area

1. Injector cleaner.2. Does it have enough miles (75K-plus) to consider changing plugs?3. What's the air cleaner look like?4. Any codes showing?Here I am trying to give answers when I probably know less than you....Good luck.

replace temp. sensor

Could be a problem with your intake air temp sensor or your coolant temp sensor. The most likely would be the coolant temp sensor. It may be reading cold and will make it run good as the engine is cold but as it warms it is not adjusting the air fuel ration to the proper levels making it run rough hot

change fuel filter located on frame in front of gas tank

There are 2 common problems on this concern. 1st maybe a dirty MAF sensor. Remove the MAF sensor and clean it with a good electrical cleaner and air dry or light shop air,then reinstall and do a couple of wide open throttle burst to reset it.
2nd problem and we see alot of this is the orings between the upper and lower intake manifold leaks.You would have to remove the upper intake manifold and replace them.

probably oil, it may be too thick when it's cold but once it warms up it liquefies and your engine runs smoothly. you could try changing oil, I'm guessing if you have a high performance oil the chances this is the problem may be greater since high performance things are usually geared towards working well when everything is hot

you might wanna use a thinner lighter oil