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Stuttering under load, power loss, stuttering boost...Help plz!

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Harpers Ferry
#1
Hey All,
Im having a heck of a time figuring this one out. Here are is the base level-2014 FiST, aftermarket I/C, 2J intake, 91k miles, COBB A/P(OTS cobb stage 3 map). About a week ago I had replaced the throttle body as it was throwing a P2111 code and had issues indicating a bad control motor. After replacing, all was good for a few days, then it started doing this. What happens seems to only be above maybe 50% throttle. The car stutters badly, and seems to be a boost issue as you constantly hear the fluttering sound through the intake(very pronounced with the 2J). It's not throwing any codes either which really has me baffled. Any help is much much appreciated!!! Here's a datalog too-
 


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Messages
14
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Location
Harpers Ferry
Thread Starter #2
OK, through more research across the boards and checking misfires, I'm leaning towards bad coil. Ive got new coils and a set of plugs on the way and I'll update then. Just putting this out there for reference if/when someone runs into something similar. Plugs were pulled earlier and checked, no signs of fouling, gap was fine.
 


TyphoonFiST

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Rich-fizzield
#3
Coils are a wear item as far as I'm concerned. They should be replaced every 50k and O2 sensors every 75k. Alot of people dont factor these into Maitenence items until they have FAILED. Coils break down and O2s get dirty especially the Upstream O2 that is the most critical in a Turbo system. Good luck!

Sent from my SM-N975U1 using Tapatalk
 


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Messages
23
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13
Location
Burke
#4
OK, through more research across the boards and checking misfires, I'm leaning towards bad coil. Ive got new coils and a set of plugs on the way and I'll update then. Just putting this out there for reference if/when someone runs into something similar. Plugs were pulled earlier and checked, no signs of fouling, gap was fine.
Did the new coils and plugs fix this issue? I’m going through something similar
 


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Location
El Mirage, AZ, USA
#5
I am also going through the same exact issue. But I am only stage 2 and other different parts. Everything on my logs seems ok with the ignition so I didn't find replacing the coils necessary, and was having my tuner help with the problem and he didn't say anything about the ignition or coils either. I'm leaning towards something wrong with the BOV. I have the turbo smart dual port shortie. I'll attach the video I got of it from under the hood the noise is on the first like 10 seconds of the video.
Do let us know though if the coils did the trick.
 


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32
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Location
Fresno
#6
I have the same issue, bought some AutoZone Duralast coil packs with a lifetime warranty and the issue came back in about a week. Went to exchange for the new coil packs and the AutoZone people were not too happy about it. So far, the exchanged packs are holding up okay. Maybe I should exchange for OEM motocraft (maybe with 2 year warranty or not, I forgot) next time the AutoZone coil packs went bad again?
 


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Location
Franklinville, NC, USA
#7
I have the same issue, bought some AutoZone Duralast coil packs with a lifetime warranty and the issue came back in about a week. Went to exchange for the new coil packs and the AutoZone people were not too happy about it. So far, the exchanged packs are holding up okay. Maybe I should exchange for OEM motocraft (maybe with 2 year warranty or not, I forgot) next time the AutoZone coil packs went bad again?
Definitely want to go with oem motorcraft.

I am also going through the same exact issue. But I am only stage 2 and other different parts. Everything on my logs seems ok with the ignition so I didn't find replacing the coils necessary, and was having my tuner help with the problem and he didn't say anything about the ignition or coils either. I'm leaning towards something wrong with the BOV. I have the turbo smart dual port shortie. I'll attach the video I got of it from under the hood the noise is on the first like 10 seconds of the video.
Do let us know though if the coils did the trick.
When my coils went bad on a decent pull it would pop really bad and shutter. Didn't throw any type of codes also. I tested with a multimeter and one resistance was off from the other 3.
 


FiestaSTdude

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Location
Cary, NC
#8
I have the same issue, bought some AutoZone Duralast coil packs with a lifetime warranty and the issue came back in about a week. Went to exchange for the new coil packs and the AutoZone people were not too happy about it. So far, the exchanged packs are holding up okay. Maybe I should exchange for OEM motocraft (maybe with 2 year warranty or not, I forgot) next time the AutoZone coil packs went bad again?
I used ngk coils from rock auto when I replaced mine. The stock coils weren't bad, but the ngk coils have performed fine so far.
 




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