Mhedja

Sold my '92 F250 4X4 and scored a 2011 2X4 F150 w/ a 5.0 engine. Now this is a new engine not only for me but it has only 16,000 miles. As soon as I brought it to Maui and drove it there is an idle jump or more like a RPM jump. First scenario is slowing down for a stop. It doesn't seem like a down shift but I am not yet familiar with this engine. Do they down shift on the automatic transmission? Feels more like when I take my foot off the gas and apply the brake the trans/engine slows down but around 1000 rpms there's this little boost up in rpms.
The other engine idle issue is driving in a parking lot at 500 rpms and I'll barely give it gas and the engine will jump from 500rpms (this is the resting idle #) to about 1000 rpms and the engine will keep it there even with my foot off the gas pedal. Anyone out there have this issue or had? Let me know, Aloha, Mhedja