to start off this is for a 22re and it has been running fine till now. It started having a high idle even when warm, and I have noticed that when I remove the radiator cap and the flow stops, the idle then drops to normal idle. When I put the cap back on and it starts flowing again, the idle goes back up. I'm stumped!!

 

Check the thermostat. It may be stuck open not allowing the coolant to get to full operating temp thus causing the idle to stay high. If the t-stat has been in there for some time, maybe best to just replace it with a new one from Toyota.

Also gave the same response in your other thread on the same issue.

 

if i could figure out how to delete this thread i would lol. i listed part of the problem i found on the other thread. thanks