Conclusion from all the feed back and actuall part replacement.
#1 throttle body failure is a known problem but rare
#2 hard to say if the failure you encounter can be fixed
#3 does not seem to be age or milage related. Fidle valve
fails because it wants to.
#4 replaced my throttle body and all is well again

and now the mitsubishi super happy bonus conclusion is

#5 my combination driving MPG has increased by 9.25%.
increasing from barely 16.8 MPG to 18.1 MPG

Thanks to all for great feedback information

ToyHooter
90 LWB Montero
Sliders, Dual Bouncies, K&N, Flowmaster, Rancho Stabalizer, KYB Gas Adjusts,
ARB Compressor Under Hood, ARB Locker Waiting Garage Floor, Spare Tire Bike/CB Ant Mount

"I didn't do it, you didn't see me, you can't prove it."
Bart Simpson