papa tiger

If you can find no damage/corrosion to it you need to see Ford. Here is the manuals info to see the ignitions operation. Trying a good used one might help. As it is a voltage HZ operational area. A break down in electrical storage/voltage or malfunctioning can be found. It could be a simple solution like the coil just isn't compatable with the transformer capacitor to replacement of the puter or re-flash trial. Your Ign may be stuck in FMEM and firing 2 plugs all the time. A good look at Freeze Frames would be helpful.

Gravyhound

Hay guys Its been a while sence Iv been on here but I found the problem about 3 months ago, 2 of plug wires were bad even though they were fairly new and every time a coil would go bad there would be a discoloration inside the coil where the plug wire slides onto the coil but I did not notice it the first couple of coils and it was the same 2 terminals or sometimes just 1 or the other, anyway I changed the 2 plug wires and it has not had the coil go bad sence. Problem solved. Im just kinda woudering why some of you guys that are certified mechanics like good ol bill with 50 years and papa tiger had me looking at things like the ECM and never sugested something as semple as a bad pulg wire. When I was at the part store getting another set of plug wires I ran into anouther guy that was also a do it your selfer like me and he said his motor would do the same thing but it was a diff. motor, coil over plug, eather a 4.6 or 5.4 cant remember and he said if a spark plug would go bad it would take out a coil. So word to the wise, a bad sparkplug or plug wire can cause a coil to go bad. Thx for every ones input guys. CASE CLOSED

callinectes

HI Thanks for the post, I am having a similar problem, Cylinder #5 went out on me this weekend, I was checking and found the coil to be dead at Cylinder #5. SO I changed the coil drove ~70 miles and it repeated on the same cylinder. I got another coil and I swapped cables for cylinders 5 and 6. Now if it is the cable it should repeat except cylinder 6 should now be the problem. If not then I am guessing it is a problem with the wiring harness or the ECU? IF it is a short would it not effect the entire coil? or is it possible for a bad ECU/harness to take out only one cylinder? Thanks

Gravyhound

I would change the spark plug and wire first unless your coil is under warranty.

papa tiger

Sorry to mess you up with all the technical stuff. Thought you could trouble shoot. Go up to the picture above and you can read " visually inspect the spark plug wires and coil. Magnify JC1 and it leads to JC2. Someone figured it out sometime ago. Hope this helps all of you out there with this constant headache. If coil doesn't fire it overheats.

closrockwell

What year is your vehicle? I have a 2005 f-150 5.4.

Gravyhound

2005 f150 4.2 v6 and still runs great, No problems after I got rid of the Bosch plug wires

harleyfltri

I just wanted to say how grateful I am for these posts and add that if you change the coil pack and have no idea how old the wires are then change them also. Had my engine rebuilt and along with it the plugs, cam and crank sesnors were replaced. A few months later on the way to Williamsburg VA the coil pack died so I replaced it. I did a physical inspection of the wires and they seemed perfectly fine so I left them alone. When I got home I actially ohmed out each wire and they all looked fine that way. A month and a half later on the way to Cocoa Beach I lost another coil pack in Georga and it was replaced under warranty. About 370 miles later I lost another one while vacationing in Cocoa Beach and was totally lost as to what the cause would be. After reading these posts and doing more research on testing the wires I saw that the wires can look good and fail once they get hot so I bought a new set of Autolite wires and put them in but the code came back anyhow. Here I am over 1000 miles from home with my Harley carried down on the back of the truck and no idea how to get everything back home. After spending an entire day troubleshooting and researching what the cause of the problem may be I saw that Greyhound solved the problems by replacing the wires so I got the bad coil pack replaced under warranty again, left the new wires on and the truck ran perfectly all the way home. FYI, I also borrowd an ohm meter from the maintinence people and checked he old wires again and they all looked perfectly fine. I tossed them anyhow and will always do the coil pack, plugs and wires together if there is any doubt at all as to their condition. I hate working an a vehicle when I'm on vacation. Thanks again!

Gravyhound

Thx. and buy the way my plug wires were less than 8 monthes old and also OHmed good also when I started having this coil problem. However in the case where you change the coil out and it runs good again but for who knows how long it can not be a spark plug because when a spark plug goes bad, it's bad, and will not run good again by changing the coil so in my case I knew it was not the spark plugs and I cant remember how many coiles I went through but I think it was 5 to 7 of them and after the first 2 or 3 I started to notice there was a discoloration in the coil terminals where the plug wires plug onto the coil and it was always the same 1 or 2 terminals so it kinda led me to those 2 plug wires. Now, I know I said I changed the plug wires and it fixed my problem and still to this day it runs great, BUT I only changed those 2. Prob. dumb on my part but anyway im just trying to be correct in what I say.

Gravyhound

Update, still runs good, when it comes to bosch plug wires JUST SAY NO! lol