1996 Kia Sportage Fast Idle Issue
Hi all! I tried to search the existing threads before posting this. Forgive me if I missed any relevant information and please redirect me if I missed something. This last year I picked up a 4 door, 1996 4x4 MT Sportage with 114,000 miles with a bad transmission and high idle issue. I fixed the transmission issue, but now I'm chasing a fast idle issue. The vehicle will start up just fine and idle around 1000 rpms. But then the idle would start creeping up to about 2500 rpms and would never come down, even after the vehicle was full operating temperature. I pulled the IAC valve, cleaned it, and put it back in. No change. Initial thought was bad IAC valve and I order another one. Installed it and same problem! So I started to look for vacuum leaks and was inspecting the larger hoses that route to and from the IAC valve. As I moved it up and down, the idle would fluctuate. I ended up finding a bad wire that went from the temperature sensor to the IAC valve plug (green with a yellow stripe). I fixed the connection, ensured good continuity and put it all back together, thinking that was the fix! Nope. Still the same problem and now it actually fast idles at 3000 rpms! If I unplug the valve, it will idle down to around 1000 rpms and run smooth. When I plug it back in, idles back up to 3000 rpms. I tried to troubleshoot the temperature sensor and I believe it is working properly. I connected the multimeter to it on continuity check and watched it slowly change as the engine got warm. I checked voltage at the plug to the IAC and have 5.02v at pin 1 (Y/G wire), 0v at pin 2 (G/Y Wire) and 0.0v at pin 3 (Y/B Wire) when cold and have 5.02v at pin 1 (Y/G wire), 0v at pin 2 (G/Y Wire) and 5.65v at pin 3 (Y/B Wire) when warm. What am I missing? What should I check? I have checked vacuum hoses and all seem to be good. I have also changed the MAF sensor because I broke it. lol! Both the old and the new IAC valve are opening completely. So what is telling it to open that much? I've tried to look up and understand that circuit and computer, but I am definitely missing something. Thanks in advance!