2005 TBird- Stumbles on light acceleration and idles rough

[Restomod73]

I got a code that #3 coil had gone bad and so I replaced the coil and related plug (set gap at .04),
Cleared the code and have driven it about 30 miles.
It stumbles on light acceleration and idles rough,
If you accelerate hard, don't feel the miss.
I am not getting any new codes.

Is there any way to tell what may be causing this?

When i removed the cover for the coils, the coil and plug, there is no sign of oil or water.
Plug was a little dirty for only 38,000 miles - it was dry and no oil residue

[Gobird]

If it were me I think I would have replaced all coils and plugs or at least the bank you had open. You can have weak coils and may not get a code. At 80,000 miles I had a stress test done on mine and all 8 coils were weak but never got any code.

[428PI]

Misfire codes on these engines don't give the correct cylinder sometimes. I'm with Gobird and replace all coils. I've chased too many and it's just a waste of time.

[Birdlover]

Misfire codes on these engines don't give the correct cylinder sometimes. I'm with Gobird and replace all coils. I've chased too many and it's just a waste of time.

Don't forget the new plugs when you change the coils.

[bsedwebt]

all 8 new coils and plugs - $60 or so - check Ebay and Amazon - work great - took about an hour

[carntz]

all 8 new coils and plugs - $60 or so - check Ebay and Amazon - work great - took about an hour

Can you tell us which brand of coils these are and if you have experience with a brand??/ THX

[BillyL]

I agree it sounds like time for you to change all the cops and plugs along with the boots and springs. Change the whole set once and delete having the misery eight times!
For higher performance I too think the Dragonfire cops are better, you can try contacting the distributer, AIP Electronics, directly at www.aipelectronics.com or call 800-261-7147.
My second choice is from NAPA auto. You can get the OEM Denso brand ( marked motorcraft by ford to cost more) or the NAPA brand Delphi.
AutoZone offers a set with lifetime warranty at about half the price of the others, but I have not had any experiences with them.
Also remember to apply dielectric grease to the plug, coil, and spring connections under the boots. I also recommend the Bosch plated body plugs and coating the threads with nickel based neversieze due to the aluminum heads. DO not over torque plugs!
Hope this helps, let us know your outcome.

[bsedwebt]

I never paid attention to the brand - for less than $5 each I could not go wrong. They work perfectly for 6k miles and if they go bad they are easy to replace and for less the price of one coil with a warranty I can get all 8. I did not scrimp on the plugs though - good ones.

[Restomod73]

Don't know the previous brand of COP's - it's the ones on Amazon.

My 2005 only has a little over 38,000 miles and is immaculate under the hood.
Sounds like I've already done most of what was suggested, except haven' replaced all.

As I noted before when you pull the COP cover there is no sign of moisture on any coil.
And the plug I pulled was clean and no oil on it.
This is 2nd time #3 went bad, so I replaced it with Delphi COP from NAPA and new Motorcraft OEM plug.
Also used dielectric grease and torqued to 12ft/#'s

I looked on Jeg's and Summit for high performance COP's but didn't find any.
Can someone tell me more about the Dragonfire COPs and if they work better and/or last longer?

Is there anything that a mechanic can use to test for bad COP's without having to remove them?

[carntz]

I just ordered dragon fire COP's. I will up date as time goes by.

[Brad]

I used to think changing all coils was just a good idea but as i found out the hard way, the system doesn't always indicate the correct bad cylinder. I took Gobirds advice after days of diagnostics and it fixed all my issues