2.3L ('83-'97) 1997 high idle

[Rooster71]

My 97 2.3 5 speed was idling high and had a code for IAC valve. I put a new one on and now it is worse. Very high revs until truck comes to a complete stop. When I unplug the IAC there is no change in rpm. I read online that the Rangers will stay idled up until it is fully stopped. I have no tach, but it seems too high. I also read that if the IAC is disconnected, it should drop to almost stalling. No change with mine. All vacuum lines are good. I don’t know if the IAC that I bought was bad. I have no idea what else to do. Any help would be appreciated.

 

[scotts90ranger]

If the IAC is disconnected and it still idles high, there's a vacuum leak somewhere through a gasket or something. Some semi common areas are a broken EGR valve, bad EGR gasket, loose throttle body (or bad throttle body gasket) or bad intake manifold gasket. That is unless some previous owner didn't like it idling at a normal speed and just cranked in the throttle stop screw a whole bunch...

 

[89Twincharge]

Get a cheap vacuum gauge and hook it up