king_coop

hey all, i need help w/ diagnostic of mother in laws 06 expd. w/ 5.4 3v. I worked for ford for 6 yrs and now work for the city and have tackled some tough jobs to diag. but this ones got me and previous ford employees stumped. I have a cylinder 2 misfire, power balanced, performed injector flow test which passed, relative compression test which passed, replaced #2 coil and plug 2 times each, swapped injectors, tested power and ground to coil and injectors good, performed decarb, reprogramed pcm. It only misses on heavy load on only one cylinder, and it spark knocks really bad when it is acting up, at idle its fine and doesnt make a noise, but at 50 mph slight hill with part throttle it missed consistant. I am about to tear down valve cover but needed some advice from a engine expert. any help will be appreciated greatly

klloyd11

king_coop,

Any luck with misfire problem? It sounds like what you described is the exact same thing my wife's 07 Expedition with 5.4 L is doing. My regular garage couldn't figure it out. Dealership said they fixed it but now, 1 month later, doing the same thing. So would like more info before I return to the dealer. Thanks for whatever info you have.

Als Brute

Hey all My wifes expedition doing the same thing only when under full throttle.When trying to pass other cars engine light flashes then i drive easy and it corrects itself but not always its an 06 with 75 miles has done it for a couple of years on and off. It seems to be more trouble when it is cold or humid outside. Truck is all stock with the exception of a full cold air intake by K&N