I need some help. I have a 2005 F150 FX4 5.4L. It has just under 50,000mi. Problem started yesterday - when idling in P or D, it idles very rough and almost feels like it's about to stall. I have an appt. set up for Thursday to get things checked out. I was just wondering if anyone knew what I should expect to hear from the dealer? Fuel pump?, fuel pressure regulator?, I know a little about cars, but not as much as most of the people here.

On a side note, my buddy has a 2007 5.4L and his has noticeably better acceleration from a stop. I thought perhaps they had an upgraded engine in the 07's but after checking specs it shows the 05 and the 07 have the same specs. I'm not sure if that has anything to do with the above listed problem as well.

Any information would be greatly appreciated - Thank you for your time.

 

05 5.4's had a bad batch of injectors. you may have a problem with one. if you do have a bad injector then it'll be replaced under warranty.

as for 07 vs 05, i know the exhaust system was changed from 4 cats to 2 cats and maybe a few updates here and there on the engine.