I have a F-150, with a V-6 automatic. The truck starts and runs fine. If you drive it 25 miles or so it will continue to run fine, but if you shut it off for 5 to 10 minutes it will idle rough and run terrible with no power. I have changed plugs, plug wires and the coil pack, with no change in performance.
Any suggestions?
Deanw

 

have you hooked it to a computer to see if it throws any fault codes? try that it may be just what you're lookin for

 

James is right. Is it giving you any light indicators? If so, Autozone will run a test for free. If not, your local mechanic can run tests for anywhere between $50-$75.

 

autozone runs free tests if somethins wrong with your truck?? Are you sure they do the "free test" if they dont have a garage?