Toyota Repair: overheating and idle, pickup 4x4, air pockets

Question
i have a 1994 toyota pickup 4x4 22re. it has been idling rilly weirdly. it reves high when not moveing and high to low rpm rappidly. ever cence it started this it has been overheating. i checked the radiator and it isnt useing much flued or smokeing. i need to find out fast. its my everyday driver and need it running clean.

Answer
The erratic idle is caused by the overheating, it creates air pockets in the cooling system and when hot air instead of coolant is read by the temp sensor the idle goes up until the sensors gets coolant again and then go down, it will just repeat. You should have the cooling system pressure tested for external leaks and checked for a blown headgasket as well.