My 2007 Ford Expediation was missing intermittenly. I changed the plugs and now it runs worse then ever. Any ideas???
I took it to Auto Zone and they used their machine to check and said that cylinder #4 was misfiring. Then they said it had multiple misfires. I even changed the coil on top of cylinder #4 and #1 which did no good.
There are a few things that could be the problem. The COP on these engines have always been a problem on the Pre 2005 engines. You couldhave gotten a bad coil. It does happen. I would have allthe coils tested for resistance. I would have all the boots visually looked at for damage. I would also replace all the plugs, and do a thurough tune up. I would also check the injectors. You could have one that is not fully opening or has been gummed up. You might want to go out and buy a coupe of cans of injector cleaner for the next 2 fill ups. You may need to replace and injector if it is acting up.
Take to Auto Zone or Advanced Auto Parts ask them to check it out with their reader. It should tell you which Coil Pack is bad. Could be a plug wire.
I have this EXACT problem right now!! Have you rectified it?? What have you found to be the problem??
I did all the usual (plugs, coils, injectors) as well but nothing worked to resolve full throttle misfire. Pulled the valve cover to find cylinder 7 had thrown 1 intake rocker.
