fast idle issues

I've had this problem a couple of times. Every time it was poor connections in the 10 pins or the TPS. Click on the link below.

http://forums.stangnet.com/698148-help-me-create-surging-idle-checklist.html

Pay attention to #2 and #6. A high idle that returns to normal after an ignition cycle is a clear indication of a dirty TPS connection or a defective TPS. Clean and tighten the terminals for the TPS connector and the 10 pin connectors. After cleaning, spread the male pins and close the female pins to increase the contact of the terminals. You only need to spread and tighten slightly. Don't go overboard! A seal pick works great for this.

Try these steps before purchasing any sensors.

I've had the same issue throttle getting hung at 2-3000 rpm on the hwy. I disconnected the iac and the issue went away completely and replaced the iac and no prob since.