Humantorch

Got this code for a fault having to do with the #3 coil. Have tried 3 different coils and replaced the sparkplug with a brand new motorcraft yet the code persists and it idles like it's definitely running on 7 cylinders.

I searched the forums for this code and the threads I've found end up deteriorating in to "try some more coils"

Has anyone else gotten this code and found the source? I'm thinking either injector or harness.

Humantorch

Side note: the brand new coils had a very strange orange colored residue on top of them but for the life of me I can't see anything dripping anywhere in the area even revving at 5k.

Fuel maybe?

BadFish523

Check the wires going to the coil.

Humantorch

I ordered a new set of wires off amazon. All 8 for $15 bucks but they wont be here for a few days.

I thought it was the harmonic balancer because I was getting strong vibration with no code. At 130k once I got the old pulley off I saw ford stamps so it was definitely the original part. Oh well lol.

redfishtd

Causes vibration symptoms . Guys have even changed their transmissions on account of this . Cheap coils ,bad boots, bad plugs . This engine very picky about ignition circuit . Codes do not set easy check input to number 3 with noid light , clean connections ,look for bad connector . indicating an open circuit to number 3 from pcm driver '.
Clean out spark hole with carb cleaner ,carbon breaks plugs going in and out .
Crank pulley is not a damper on this engine just simple pulley .

Humantorch

There's rubber inside the harmonic balancer so it must be doing something. If it doesn't dampen vibrations wouldn't they call it something else?

Unfortunately changing all 8 plugs and coils is what caused these symptoms.

The wiring harness is 15 years old so unplugging the coil/disturbing the wire must have broken it somewhere.

I used carb cleaner to clean out the sparkplug wells, threads and cylinder, then sucked it out with a dry vac. It was so clean the new plugs threaded in by hand. I then tightened to 20ft lbs.

Humantorch

Update: Fixed the issue. The spring that snaps up in to the coil wasn't seated properly. The code is gone but it still idles like a massaging chair.

BadFish523

Probably still has a minor misfire somewhere. Might be worth it to go through all the boots,springs, and coils to make sure there isnt another loose connection somewhere and everything is nice and clean. Not all misfires will throw a code. Also did you disconnect the battery? Did you do the relearn process after if so?

Humantorch

Yes I do a relearn after every parts change.

After installing the new plugs I ran a can of seafoam through the motor by way of the throttle body. Is it possible seafoam killed a few plugs? I pulled and tested all the connectors before finding out about the #3 spring issue and they are all good.

BadFish523

Do you have an Android device? If you do, I suggest you get a bluetooth OBD2 transmitter and download the Torque Pro app. With these two items we can tell exactly which cylinders are misfiring and how much. Plus you can use this setup to read pretty much every PID in the truck.