Cops

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Sep 10, 2008 | 09:27 AM

dantsg

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Joined: Mar 2008

Posts: 147

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From: Miami Lakes, Fl

Cops

I changed the cops last week and the truck ran great. 1998 5.4.
Now it is starting to run rough around 30 mpr - 45 mpr.
any ideas

Sep 10, 2008 | 10:05 AM

KingRanchMan02

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Joined: Oct 2005

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From: Louisville, Kentucky

Could be a bad new COP or a bad spark plug. Good luck!

Sep 10, 2008 | 10:40 AM

Bobby82490

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Joined: Dec 2006

Posts: 1,466

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From: N. Fort Myers,FL

Quote:

Originally Posted by dantsg

I changed the cops last week and the truck ran great. 1998 5.4.
Now it is starting to run rough around 30 mpr - 45 mpr.
any ideas

What brand did you use? You might have a coil shorting out, even though they are new. I have seen brand new parts be defective right out of the box.. so dont excluded an already failing coil, yet.

Im guessing you arent getting a check engine light so you might have to start by unplugging each coil till you find the one that is missing.

One more thing, how old are the plugs?

Sep 10, 2008 | 01:35 PM

dantsg

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Joined: Mar 2008

Posts: 147

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From: Miami Lakes, Fl

The plugs are about six months old. The COPS are an ebay deal that sounds like was not a good go.

Sep 10, 2008 | 06:16 PM

galaxie641

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Joined: Nov 2006

Posts: 4,517

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From: SE Wyoming

The ebay COP's are fine I've been running them for over 10K miles with no trouble as have many others. You could always get a bad egg in anything. I'd guess one wasn't attached very tight and came loose. Either way it would be easiest if the CEL would come on and at least tell you what cylinder it is.

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