I am having a low idle situation ever since it started getting cold here. It started the morning where it hit 15 below (before this cold day, never had any issues, and idled at around 7-800), and my 86 4Runner started idling at 500rpms. It runs great and doesn't have any problems once it gets going, just at idle.

Only thing I recently changed was the oil to 5w30. Other than that, I haven't made any changes. What could be causing this low of an idle all the sudden because of cold temps?

 

There are multiple threads on this problem but it sounds to me like it is your cold start system. ie: cold start injector, cold start timer switch, cold start temp sensor, or the auxillary air valve. Does The exhaust smell like it is running rich? If so I would check the aux air valve to see if it is opening up. It has a bimetal spring and a rotating plate that opens and allows more air to flow into the intake when it is cold. Mine was really sticky so I cleaned it with a little carb cleaner and it works a lot better.

 

Wouldn't most of those parts you listed go away after the engine was warm though? I am not too familiar with the 22re, but it seems like most of those would be for the first few minutes of start up, and not after 20 minutes of driving. Exhaust does not smell rich, but i will double check again.

 

Yes, those components should shut off once the engine coolant has warmed up to operating temp. You might try adjusting the idle once the engine is warm. Check all of your vacuum hoses and electrical connections to make sure nothing got accidentally disconnected while you were working on it. You never know.