Coil problem

[panteramatt]

My wifes 3V mountaineer has had a bad miss for a long time now. It seems fine until around 40-60 mph where it bucks and misses bad. I replaced all the plugs and it went away for a while but its back again. So far Ive replaced 3 of the coils with the accel coils but its just a shot in the dark really. Can you guys tell me an easy way to check the coils or cylinder to see which one is truly the culprit?

 

[Ornery]

Hasn't it thrown a code yet? Being intermittent makes it a bugger to track down. If you can get it to lug enough to trip the CEL, it should pinpoint the cylinder when you pull the code. Hold down the brake while driving until it starts missing and try to keep it missing til the the CEL flashes. Even if the light isn't on steady, it should store the code that made it flash on. It may already be in the memory.

 

[NORDFORD]

My wifes was doing the same thing. I removed the plug boots from the coils, filled both ends with dielectric grease and it went away. Look towards the bottom of the first page topics in this section. There is discussion of torque converters going out, your symptoms don't sound too far off.

 

[panteramatt]

No CEL. Ive had the same problem for a long time now. Had the tranny checked out by ford a while ago and they said it was fine. They said it was a coil. Replaced 3 of them so far and changed th eplugs and it ran great for a couple months but now its back. I still think its a coil. I just wanna know how to track down a bad coil so I dont have to keep replacing them if their still good.

 

[Ornery]

There are ohmmeter readings for verifying a bad coil, but the coil won't be under load, so it won't be conclusive. Can you check the memory for an existing code? Have a scanner? If not, how about getting one of these "AutoTaps", and let me know if it's any good?

While hunting for the ohm meter tests, I stumbled on to a really interesting troubleshooting video, "Finding an intermittent".

How to Test the Ford 4.6L, 5.4L Coil-on-Plug Ignition Coils

Edit: Forgot to mention, run some good fuel injector cleaner through there just in case that's the problem.

Edit II: Find somebody with a "LabScope". No code misfire

 

[jupiterak]

No CEL. Ive had the same problem for a long time now. Had the tranny checked out by ford a while ago and they said it was fine. They said it was a coil. Replaced 3 of them so far and changed th eplugs and it ran great for a couple months but now its back. I still think its a coil. I just wanna know how to track down a bad coil so I dont have to keep replacing them if their still good.

I had the same problem for a few months. And no matter what I tried, I could NOT trigger a trouble code. My Ex only has 60K miles on it. It happens between 45-53mph at around 15% throttle. At first I believed it could be the torque convertor/tranny. But after reading some owners changed the plugs and coils, I went that route instead. It worked cause I haven't had any issues for over 4k miles now. I went with Motorcraft SP-514 plugs from Amazon and got the coils off ebay for $75. I was worried since they're cheap but they have a lifetime warranty and had no issues so far.

http://www.ebay.com/itm/360401087174?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

[panteramatt]

Yea Im fairly certain its a coil. I just need to find which one. Ive already replaced 3 with teh accel coils and Im sure I need another one but at $42 a pop Id like to be certain.

 

[Ornery]

$75.00 for 8 COP's?

And Free Shipping?!​

 

[panteramatt]

Yea Im just wondering if their truly motorcraft coils though.

 

[Ornery]

They're not, they're probably Herko. But, if you still have the coils that the Accel coils replaced, start swapping them in. If you have all three, it will only take two tries at the most to nail it. Basically, you've already spent all the money you need to.

 

[Laserbait]

Probably chinese knockoffs, what could go wrong? I'd pass on the "deal" myself, but I'm not hip on constantly replacing dodgy coil packs. I've got better things to do.


From the Ebay ad:

8 Ignition Coils made by Empyrean Auto Parts


The EmpyreanAutoParts.com website is down or non-existant. The WhoIs record (http://whois.domaintools.com/empyreanautoparts.com) for them doesn't give me warm fuzzies either, because normally, a legit business will not use a privacy service for their Domain Registrant Info:


Registrar: FastDomain Inc.
Provider Name....: FatCow Web Hosting
Provider Whois...: whois.fastdomain.com
Provider Homepage: http://www.fatcow.com/

Domain Name: EMPYREANAUTOPARTS.COM

Created on..............: 2011-03-16 00:45:14 GMT
Expires on..............: 2013-03-16 00:45:14 GMT
Last modified on........: 2012-03-01 13:23:34 GMT

Registrant Info: (FAST-15019521)

Domain Privacy Service
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Phone: +1.8882789780
Fax..:
Email:
Last modified: 2012-05-18 20:52:52 GMT

Administrative Info: (FAST-15019521)

Domain Privacy Service
70 Blanchard Road
Burlington, Massachusetts 01803
United States
Phone: +1.8882789780
Fax..:
Email:
Last modified: 2012-05-18 20:52:52 GMT

Technical Info: (FAST-15019521)

Domain Privacy Service
70 Blanchard Road
Burlington, Massachusetts 01803
United States
Phone: +1.8882789780
Fax..:
Email:
Last modified: 2012-05-18 20:52:52 GMT

Status: Active

Domain servers in listed order:

NS1.FATCOW.COM
NS2.FATCOW.COM

 

[willied]

Make sure there's no moisture in the #8 cylinder/coil area. How many miles do you have?

 

[panteramatt]

91k. #8 is the farthest back towards the firewall on the drivers side right?

 

[willied]

91k. #8 is the farthest back towards the firewall on the drivers side right?

I think so. It's either that or the one right next to it (passenger side). Have you had your plugs replaced yet? I would think it would give you a CEL if it was a plug or coil problem, but maybe not.

 

[Town]

91k. #8 is the farthest back towards the firewall on the drivers side right?

Right.

 

[panteramatt]

Yes. I stated in my og post that I replaced all the plugs and it ran great. Now after about 3-4k miles, the miss is back. Thats why I think its a coil.

 

[Town]

Yes. I stated in my og post that I replaced all the plugs and it ran great. Now after about 3-4k miles, the miss is back. Thats why I think its a coil.

It has been known for a plug to fail, or back out of the threads. I would check the plugs and make sure there is no moisture in the plug wells. Check for damage to the boots.

Good luck

 

[06explorerEB]

My wifes 06 explorer has this same problem. Done quite a bit of reading on and replaced the plugs and still no change, bucking around 40-50 mph. No codes showing, no pending codes. My mechanic thinks it could possibly be the tc. Any ideas on what to check?