COP issue question

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Apr 19, 2017 | 08:21 PM

Murf_2002_F150

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COP issue question

I have a 2002 F150 supercrew 4x4 with Triton V8 5.4 liter engine. We only drive it when we need to haul something. About a month ago the wife was driving it and she said it was shaking and running rough and the check engine light came on. So I pulled the code and it was the one that says P0301 cylinder 1 misfire condition - an issue with the COP or fuel injector as I understand it. It has set for a month (except to pull garden tractor out of mud it was stuck in). Today I ran it over 3 miles at 55 mph with check engine light still on. It ran fine.

My question. Is that normal when a COP is going bad - instead of completing failing it will work sometimes and not others?

Also, I was looking for a COP online at auto part stores, but wasn't sure what to search for to get the right part. What words should I search with?

Thanks

Last edited by Murf_2002_F150; Apr 19, 2017 at 08:27 PM. Reason: Clarification

Apr 20, 2017 | 09:35 AM

alloro

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You can swap the COP with another cylinder to see if the code moves before buying a replacement. Also, it could be a spark plug, but as far as the COP goes, look here: 2002 FORD F-150 5.4L V8 Ignition Coil | RockAuto

Apr 20, 2017 | 03:43 PM

Murf_2002_F150

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Thanks for the reply and link.
I'm thinking the plugs are ok because I had them all replaced last year and they don't have many miles on them.

Do you know if COPs normally go bad all at once or is it possible they would work sporadically before finally stopping altogether?

Thanks

Apr 21, 2017 | 01:18 AM

R&T Babich

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From: Thousand Oaks, CA

Quote:

Originally Posted by Murf_2002_F150

... Do you know if COPs normally go bad all at once ....

The boot/spring part of a COP will usually degrade before the coil goes.
I change plugs/boots/springs at 50k and use Denso boots/springs.
Still have original coils with 165K.
You can get a set of 10 Denso 671-0001 boots/coils on ebay for $29.99 no tax, free shipping.

When your wife drove it with the problem had it just rained?
A little water down in the plug well can cause a misfire and after a month it would have dried out.

Apr 21, 2017 | 08:19 AM

alloro

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Quote:

Originally Posted by Murf_2002_F150

Do you know if COPs normally go bad all at once or is it possible they would work sporadically before finally stopping altogether?

There is no rhyme or reason to them failing. They can go one at a time or all at once. I've seen several fail after a spark plug change simply because the COP boots were stretched. The stretching can cause micro splits in the rubber and allow spark to jump sideways to the plug well wall instead of down to the plug.

Apr 21, 2017 | 08:51 AM

Murf_2002_F150

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Thanks guys. That is helpful.

Apr 21, 2017 | 10:00 AM

R&T Babich

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From: Thousand Oaks, CA

Quote:

Originally Posted by alloro

Good point about stretching the boots.
You're talking about just the boots failing, right?
The coils should still be good?
The only bad COP coil I've had was where the base of the connector broke at the housing.