Download Winstar 2001 idle revolutions

Greetings to all in the forum, my problem is the sig:

I have a 2001 Ford Winstar every time it starts with the engine very accelerated as 1700 rpm. This causes that when putting the reverse or drive the box kill it a lot after using it for a while the revolutions fall like at 800rpm. Are there any way to lower the rpm? I thank you in advance.