My wife's 5.4 Expy started running rough a couple weeks ago. It seems to run fine when cold, and then quickly gets rough after several minutes of running. I pulled the codes and it appears #7 is misfiring..307. I underdstand there is a coil over each plug. I suppose testing the coil over #7 would be the first step.

How do you get the coil off? There is a little bolt burried under the EGR feed, under several hoses, and under the fuel rail. How do you get to these bolts? Do you take the fuel rail off or just work around it? I'm used to working on Mustangs which seem to have a lot more room.

Any advice on this basic one would be great.

 

It looks like there's no room but it's not as bad as at looks. It should be similar to my 2000 F-150. 7mm socket to remove the bolt, then gently pull cop towards the fender to get it out from under the fuel rail and pull straight up. Some say you should replace the plug as well due to carbon arcing. Autozone has the complete cop for about $50 (aftermarket) and there's a guy on ebay that sells them for $28+ (MotorCraft).
Be sure to use a liberal amount of dielectric grease inside the boot to seal the plug.

Sean

 

Pull the plug and check its condition at the same time. While Fords claims that the plugs will last for 100,000 miles they don't say anything about the boots. You should also check the coil boot for signs of arking. This will destroy a coil real quick.

JMC

 

OK...I'll stop whining and just climb in. Glad to hear I don't need to disconnect the fuel rail. Probably need to get an elbow for the socket though.

Thanks!

 

If it helps you can pull the fuel rail. I have changed my plugs before and it made it alot easier. THe fuel rails and FI's came off and went back on with little stress.

Just another opinion.... good luck.


PS- I had number #4 misfire and it turned out to be a split boot.... cost 10.00 dollars!!!