Erratic idle, '93 explorer, 4.0
 

Looking for a little help here. '93 explorer sport, 4.0, 5 speed, 360,000 miles, well maintained. Plenty of power, and uses no oil. Hard to believe, isn't it. Idle will not drop below 1100 rpm. I've changed the IAC and the TPS. The IAC was a mess, and the TPS checked out bad. When I decellerate the RPM drops and then raises about the time, it's time to turn a corner. This being somewhat annoying, I'm looking for a solution. I'm getting between 18 and 19 MPG the engine is running like a finely tuned swiss watch. Just put plugs and wires in it and am healing rapidly. Looking for some suggestions.

I had somewhat the same problem with my '94 Sport. Mine turned out to be the computer, which monitors and adjusts the idle speed.