3.4L Toyota TacomaIAC Valve

I need some advice. My Tacoma is idling very weird. It idles up and down all the time. You can put it in first gear and let it crawl but then it will take off without pressing the gas and then will idle down shortly after, without doing anything. It is like you are punching the gas and letting off, punching the gas and letting off. I thought it may be the temp. sensor also. I took the IAC off and cleaned it and it did OK for about half a day. So I started the truck and unplugged the IAC, the truck went to a low idle, but with it unplugged you can tell it doesn't run quite right. So i plugged it beck up and the idle shot up. Do I need to go ahead and replace the IAC or is there anything else that I can do to check. The are no vacuum leaks I have found, Any help will be greatly appreciated.

THANKS

The YEAR MODEL might help in getting info....

Thanks, It is a '98

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Sounds like the iac is sticking,when the ecm sees a higher than normal idle it will disable the injectors momentarily to bring it down this is why its surging,but is the check engine light on if so find out what the codes are and double check for vacuum leaks

I am an idiot, I ran the code a while back and it did come back to the IAC valve. It has been a while since I ran the code and I had forgotten about that. Thank Ya'll for the help.

Thanks, Eric