I saw this same issue posted in the archives from 2002 and now I am running into the exact same problem and having difficulty diagnosing the real problem...
"when I first start it in the morning it works fine. After 30 minutes of driving I stop the engine. After I come back (20 min later) I restart the engine. The engine idles very rough. It seems like it wants to die. It idles just above the 500rmp marker".
Has anyone else run into this problem - any suggestions? Thanks -
4RunnerTampa