i have an 89 civic cx that is driving me insane. The car's idle is totally messed up and i have no idea why. It will idle from about 700 rpm then shoot up to like 4 or 5k and stay there then go back to fluctuating between 800 and 1500 rpm.
I have already gone through 2 iacv valves cleaned them both throughly and got new gaskets, bled the coolant, checked the whole engine for any vacuum leaks. im picking up a used throttle body with another tps sensor soon but besides that is there anything else that could be going wrong? oh and its throwing no codes.

 

its prob the TPS...if you changed the IACV and no vacuum leaks than its your TPS