I'm having an issue with my 4.6. it runs fine until I get about 40 to 50 miles in and then it starts running horrible. Almost like it's misfiring or running out of gas. No throttle , if I turn it off for 5 minutes or so it runs fine again. I've put new plugs and coils about a year ago, new fuel pump and filter about 3 years ago and all of the evap system is new. I'm stumped. any suggestions?