Back to working on the Ranger. I have a 1998 Ford Ranger V6 4.0 which was rebuilt with a short block about 30 thousand miles ago. A few months ago I started having trouble where the idle would remain high when I was at a stop sign or light. It didn't this all the time but every once in awhile. We talked about it here and after a few ideas I replaced the throttle cable which seems to have remedied the issue. I then started hearing a buzzing sound around my air box which I researched and discovered it was the idle control valve. After changing the IAC the buzzing was resolved. Feeling brave I then cleaned the throttle body with throttle body cleaner. Sadly I left the throttle body on the truck and was amazed at how caked on the varnish was. I also did not take off the throttle position sensor which was a rookie mistake since I think the cleaner may have gotten into the TPS. After doing this I noticed my idle stayed elevated when I came to a stop until I let out the clutch. I'm replacing the TPS and I think I should replace the throttle body. I removed it from the truck and sprayed it with throttle body cleaner and used a wire brush but it still has a lot of burned junk on it. Also the vacuum port was very dirty. 

Do you think this will solve the new idle issue? I don't like to be just a "parts changer" but it seems logical with the issues that perhaps the TPS is bad and the throttle body may be getting stuck because of the grim. The truck is my project while I'm in school (working on my auto tech degree) and I only bought it 15 years ago so I want to exam and diagnosis this problem correctly. Thank you for your help.