My 09 F250 super duty will run just fine when the temperatures are cool, say below 75 degrees. Let the ambient air temp warm up and the computer goes into limp mode; I loose cruise control, acceleration and mpg drops. I have replaced the Mass Airflow sensor, no change. Cannot figure this one out.

Did you install a new chip? How many miles are on the truck? Sometimes, fuel pump head clearances increase and fuel pressure drops on old, tired pumps. Have you checked for codes?