weird problem on cold start (dangerous)

[sask08]

Has anyone ever had there truck rev up unexpectantly while going through the shift pattern on an auto? More specifically when going from drive or reverse into nuetral or reverse into park? The only time this will happen is when using the gear selector. It revs up to 1900 rpm almost like its going to run away and then back to an idle. Its very scary if you going quickly through the gears and stop in reverse or drive because it causes the truck lurch forward or backward if you don't have your brake pedal pressed through the floor boards.

By the way, my truck is a job1 08 f350 diesel 4x4 with an auto. It is spartan tuned aswell.

[ajpu1983]

I had a Dodge doing the same thing and it was the torque converter