first, make absolutely sure you have no vacuum leaks, good O2's, and that the MAF is clean. Next, remove the idle air control valve and place some sort of block off there. A business card works well when sandwiched between the valve and TB. Adjust the idle speed, not sure about the V6, but the 5.0's are 700-750 ish. next, get your multimeter out and probe the TPS signal wire (should be the middle one IIRC) and attach the other to ground. Check your service manual for the correct voltage at idle spec (you can do this with the key on, engine off) and if it's right, then pull the "blockoff plate" from the IAC and drive away. If not, then loosen the 2 screws holding the TPS to the TB. If you can adjust it far enough to get into spec then do so. If not, carefully and slowly notch the holes in the TPS so you can bring it into spec. If you have to remove more than about 1/16 inch, then you have other problems you need to fix first, ie vacuum leaks. Good luck!