Hello my name is James and this is my first ford. I bought it and changed the fuel filter and it was dirty. Then ran a tank of gas with seafoam and then with lucas fuel injector cleaner. Still nothing. It idles like its missing and as long as you are light on the pedal it revs up fine but if you're heavy on the throttle its ****ty. Its has no codes that's why I haven't replaced the coil packs and plugs but they have been ordered. I just thought there would be an engine code if any of the coils or plugs were bad. Looked for a vacuum leak but couldn't find any. The donut gasket on the pass side is bad would that cause it to run shifty with no code. Any help is greatly appreciated

 

Hope somebody has better answer than mine but here goes. I picked up a used rental with a ton of miles on it. Ran some Seafoam thru it, probably first time it ever seen any cleaner. Started to run rough maybe 100 miles later then thru a mis-fire code. Turned out Seafoam maybe cleaned it out to good. Fouled injector. Then some miles after getting fuel injector cleaned it later did same thing again. Both were on passenger side second hole back for some reason.

I now change fuel filter every 3,500 miles and no more problems (so far).

Fuel injector shop where I go loves Seafoam, keeps him in business, he has many stories.

I also checked other stuff (COP, COP connections, cleaned MAF etc) before blindly removing fuel injector.

There is a good write up on changing plugs on this forum somewhere, it came in real handy for me. Don't know where to locate it now though. Maybe a search.

 

welcome to FTE.
if it is only an occasional misfire, it will take time ot throw a code.
sometimes my crown vic and 04 5.4 powered F-350 will run bad for a month before it throws a fault code so i can change the coil.