Help with my 84 GMC Sierra(automatic)

I am having problems with my truck and I think it may be my tranny. When Im driving my truck it starts idling really high and it doesn't want to change into the next gear. You have to continue pressing the gas until it hits 30mph, you have to let go of the gas and press the gass again to change gears. It starts driving fine after I do that? Im wondering if anybody could tell me whats going on and if you guys have any ideas what I can do. Thanks

Would you suggest a transmission tune up?

Many things can cause this, an out of adjustment throttle cable is the first thing to check.

ok so i went to check what you said and It found something. This is what I found.
http://i153.photobucket.com/albums/s222/silvinochavez480/011.jpg
So I replaced it and It was doing the same thing.
http://i153.photobucket.com/albums/s222/silvinochavez480/015.jpg

SORRY FOR THE BIG PICTURES...:uhoh:
Well I noticed that when I accelarate the gas that little arm I replace doesn't accelarate with it it just stays in place. Should it move with it or its just there for something else. Here is a pic what it puts pressure to if it did accelarate.
http://i153.photobucket.com/albums/s222/silvinochavez480/017.jpg

Don't post pics that large, please. You are pointing to the cruise cable, the tv cable is the one closest to the throttle body with the braided wire coming out this needs to be checked and adjusted, I suggest you get some help with this.

sorry about that I just wanted for you guys to have a close look. I didn't want to have a pic not able for you guys to see. The problem is that it doesn't want to get out of the first gear. Ill look more into it tomorrow cause no daylight. Thanks for your suggestion.