I'm having the same problem with my 95 SE 2.5L. I checked it with an NGS and noticed the BARO, barometric pressure, reading was at 150Hz which translates to about 5000 feet above sea level? I'm at about 450 feet. Now the Tours don't have BARO sensor but they infer the reading from the MAF and TPS through a lookup table. This reading will get updated when you perform a WOT. I did some WOT's but no change on the reading. I disconnected the MAF and started the car and the idle prob went away. By disconnecting the MAF the vehicle looks at engine RPM and TPS to correct Air/Fuel mix. I installed a new MAF but disconnected the battery for a Min of 5 minutes to reset the computer. I also found a collapsed hose leading to the PCV valve. I restarted the vehicle and noticed I still had rough idle problems so I did some WOT. 10 to be exact and my BARO readings updated to 159Hz or about 500 feet. The tour runs now, just finished it, but every so often it seems to hunt for the correct RPM like it is trying to learn a new idle. I'll find out tomorrow morning when I do a cold start if I found everything that was wrong. In short, even though the MAF looks good it doesn't mean much, mine was way out-of-wack. Also watch for the pesky PCV collasped hose.
