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Unread 12-18-2011, 07:30 PM   #1
Rocklobster
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Cylinder 5 and 6 misfire
Need help on cause and fix please, I have yet to pull the plugs as I just read the codes this evening and it's 25° outside but I wanted to get some info. Thanks,Rich

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Unread 12-19-2011, 04:46 AM   #2
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Bump for the am

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Unread 12-19-2011, 07:04 AM   #3
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Engine details please? 4.0l or 4.7l?

A misfire is usuallly caused on the HT side of the ignition and causes the cylinder to fire out of sequence therefore things that can cause it are:

Faulty HT Leads
Weak coil - Reduced spark at the plug
Worn/fouled plugs - i.e oiled up!
Broken electrodes off the plug
Dampnes in the HT lead - remove them and bake in the oven then spray liberally with Duck Oil or WD40 whilst hot! (It won't go up in flames! Done this many times.)
Dampness in the Dizzy (Distributor Cap) again bake in oven..
Hairline cracks in the Dizzy..
Faulty electrode pack...

Hope this gives you some ideas where to look.
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Unread 12-19-2011, 08:29 AM   #4
Rocklobster
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Sorry 4.0L thanks gonna try and do the plugs

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Unread 12-19-2011, 03:40 PM   #5
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Swapped out the plugs to the right ones and light stayed on. Disconnecting the battery to see if that will reset the ecm. Coil pack was replaced a year or so ago, that guy was a duche. Coil pack again maybe IDK. thanks guys

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Unread 12-19-2011, 03:47 PM   #6
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Hi again,

Take each spark plug out and connect to the lead and turn over holding the plug to the block and see how the spark behaves. Does it spark all over the place, is it strong etc.

Remember to wear gloves and hold with pliers or rest the plug and lead on the block/rocker cover - The HT gives off a nasty kick if not done right!

In the dark, crank the engine over, and look for arcing in or around the plug socket..

Keep us posted!
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Unread 12-20-2011, 06:05 AM   #7
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Update, after changing the plugs and disconnecting the battey the light is off, also I took it for a 30 minute ride of highway and city and the light remained off. I hace my girl watching it today in her travels. Thanks guys, Rich

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