Mitsubishi Repair: idle surges up and down and and fast, idle air controller, speed controller

Question
I have a 1990 Montero 4x4 V6 3000 when I first start it up it idles fast and then it starts to lope surging from 1200 to 1500 rpm's.Under any kind of a load,ie.shifting into drive,AC it goes into a steady high idle without the surgeslopes.I took it for a two mile drive and it runs well-passing gear acceleration etc.

Answer
Ricardo,
This sounds like a problem with your idle air controller (IAC), also known as the idle speed controller.  This component is attached to the throttle body and regulates the idle speed when the engine reached its normal operating temperature.  When that component fails, it will keep searching for the proper idle speed and that causes the surging.  Have a mechanic inspect the IAC and replace if necessary.
Good luck!