miss fire issue

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Feb 24, 2013 | 10:44 PM

SMonroe

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Joined: Feb 2013

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miss fire issue

looking for a little help.

2004 F250 SD 4x4 109k miles

Truck developed a really bad miss no codes. Changed the plugs, coils, boots, fuel filter, injectors, and air filter as well as cleaned up the intake and PCV. Truck ran great for about 200 miles but now i have a random miss at low RPM worse when cold and under a load. I changed the MAFS and it seemed better but still not 100%

Any suggestions.

Feb 25, 2013 | 12:03 AM

jh818

Cargo Master

Joined: Jul 2009

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From: Chino, California

No water in the spark plug holes?

Feb 25, 2013 | 05:50 PM

SMonroe

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No water in the holes I pulled all the coils the other day to see if I had that issue or maybe damaged a boot during the install. I didn't see anything wrong.

Feb 27, 2013 | 05:28 PM

86ford302help

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Joined: Dec 2011

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From: East Bernstadt Kentucky

what does it mean when there is water in the holes? I have a 2001 5.4L and i have a slight miss fire sort of on and off. when i pull the coil pack then there is water in the hole.

Feb 27, 2013 | 08:11 PM

jh818

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Joined: Jul 2009

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From: Chino, California

Quote:

Originally Posted by 86ford302help

what does it mean when there is water in the holes? I have a 2001 5.4L and i have a slight miss fire sort of on and off. when i pull the coil pack then there is water in the hole.

Water in the spark plug holes means that most likely is the cause of your misfire. The rubber of the boot insulates the spring inside from the negative ground (engine block). That water becomes a conductor and shorts the 2.

It's kind of like the same reason they say to get out of the swimming pool when there is a thunderstorm.