2011 lariat ecoboost misfire issue
11-10-2015, 12:50 AM
#1
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2011 lariat ecoboost misfire issue
So I bought the truck used with 87k on it. At 100k I had misfire issue with cylinder 5. I pull the plug and it has a black stripe down the side of the plug on the porcelain section. I have been chasing plugs ever since in every cylinder. Changed all six coils and plugs and it came back after a hit a rain storm. My intercooler has no signs of moisture nor does my intake pipe. Anyone have any ideas? Also my positive side terminal corrodes really fast it seem. Truck has had the stretched timing chain issue and 2 new turbos before I purchased it. Purchased the truck in the spring of 13 and has been a headache. I
11-10-2015, 11:39 AM
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Why would the spark jump from the top of the plug to the head without going through the plug if I overtightened it? I've ran motor craft plugs and tried the auto lite plugs and both do the same. I'm doing a turbo swap cuz I blew my right side turbo but when that's done I ran a ground wire off the battery to a bolt on the side of the block and I'm hoping that takes care of it. This has been a problem from day 1.
11-10-2015, 12:00 PM
#4
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If the plugs are cracked, spark will leak out causing a misfire. Its very easy to crack them, I have even using a torque wrench. What are you tightening them to?
11-10-2015, 12:30 PM
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And plugs don't crack just carbon tracking on the side of the porcelain. It only causes misfire at wot and any position close to wot. Otherwise truck drives fine at cruise. I'm nervous to make a pass bcuz it starts to shutter the further I go down with accelerator
11-10-2015, 12:35 PM
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I have a 3/8 torque wrench but have never used it on the plugs. But torquing the plugs is another good idea to try. Also I haven't tried anti seize. Will let you know when it's running and if it continues to do the same thing. Until then I get to drive ol reliable!
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11-11-2015, 12:37 AM
#9
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What are you gapping the plugs too?