I have a 88 4runner v6. It has developed a strange idle problem. It started by idleing up and down when the brake was depressed intermittently. and now does it all the time although it goes up and down at a higher rpm range with the brake not depressed. when i say up and down i mean it will go up to 1100 rpms and the cut out down to 700 rpms and then back up. that is with the brake pressed. when the brake isnt pressed it goes from 1300 to almost 2000 rpms. any ideas?

 

I think I saw your question somewhere else this A.M., but wanted offer this info. My Throttlebody screw started turning itself a while back due to a worn O-ring and engine vibration. I recently replaced the O-ring and the screw stays in place. Your problem may be more complicated that that, but just in case it isn't I hope this helps.