I have a 1998 Dodge Ram 1500. It has started running roughly and will not idle.

What is your question?

I took off the IAC valve to clean it and it was not dirty. I cleaned it and replaced it. Then l took out and checked the air filter. It is okay. Also the transmission has started changing out after running up to high rpms. Could this be overdrive issues? Would overdrive issues stall an automatic transmission and kill the motor? Also if l am driving and keep my foot on the gas and let the motor run above 1800 rpms it stays running, but if l take my foot off of the gas it goes dead even driving down the road at highway speeds. Also if l slow down and turn my steering wheel over 90° it will kill the motor unless l hold the rpms over 1800. Also when l take off from a complete stop the transmission whines and jerks.

What makes this problem better or worse?

When the engine first cranks it will idle until you push on the throttle.

How long has your 1998 Dodge Ram 1500 had this problem?

About a month