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Bad MPG After Plug Change

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Old 08-18-2015, 12:54 PM   #1
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Default Bad MPG After Plug Change

I have a 2011 EB FX4 with 112k miles. I should have changed out the plugs a long time ago but, well, shame on me. A few weeks ago I got a blinking CEL and a misfire when goosing her. Took her to my local dealer and was told it was coding for plugs. Dealer quoted me @ $650 for a tune up (plugs, boots, and carbon flush). Thought this seemed high (especially when a dealer across town quoted $198 for plugs and boots). Bought new Motorcraft plugs and boots at Autozone last week and changed them myself last Friday (I did not even attempt to gap them to the .028 recommended in a YT video I watched). Truck definitely seems to run better but the mpgs are sucking. I don't drive this vehicle hard at all (never tow and except for fall rifle season, never off road and even that's light). New the vehicle was avg @ 19 and lately it's been @ 18.3. After plug change it's been hard to get above 16. Any ideas?
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Old 08-18-2015, 12:56 PM   #2
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First of all, gap the plugs properly. Second, did you grease the springs and seat them well? And was the battery disconnected while you did it?
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Old 08-18-2015, 01:25 PM   #3
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I did put DE grease on the boot springs and seated them properly. Batt was not disconnected. Again, I did not gap them (what are the factory MC plugs gapped at? Tried to find an answer to this and could not).
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Old 08-18-2015, 01:52 PM   #4
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I'd call a Ford dealer and ask them.

That aside:
http://www.f150forum.com/f72/battery...rocess-133736/
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Old 08-18-2015, 02:45 PM   #5
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Quote:
Originally Posted by Rooster Cogburn View Post
I did put DE grease on the boot springs and seated them properly. Batt was not disconnected. Again, I did not gap them (what are the factory MC plugs gapped at? Tried to find an answer to this and could not).

anywhere from .030 to .032
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