Misfire Issues

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Misfit_1122

Misfit_1122

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Update.....

I couldnt find the culprit regardless of which spark plug/ignition coil switch I did. Brand new oem plugs gapped to .028 (triple checked using two gap tools). Still no luck........

I finally broke down and disassembled the ignition coils and boots to remove the spring retainers inside the boot. To my surprise the entire middle portion of the spring was filled with what looked like hardened die-electric grease. I thought this was odd so I took a pipe cleaner and cleaned it out with the help of electric connector spray cleaner.

So far I have made 10 back to back WOT pulls to include two hard launches from a stop all the way out to the limiter and up to 107 mph. I said screw it if its gonna blow might as well be today lmao.....

The truck is pulling hard all the way through each gear and all the way up to 107..... Needless to say the truck is performing as it should and I'm glad to have found what seems to be the culprit to my constant misfire issue. Cant wait for my stg2 hardware to go on next week.

Shout out to @wgr73 to being right there through the whole process again. You rock man.....
 
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TwizzleStix

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Yeah, we might want to make this post ^^^^ a sticky. This likely isn't the first time this problem has shown up. I think many of the folks who have a lot of misfires and swear the 542 plugs are so great have this issue without realizing the root problem. It can certainly be on random cylinders and intermittent as well.

Great diagnostic/troubleshooting @Misfit_1122
 

GooseTuned

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Update.....

I couldnt find the culprit regardless of which spark plug/ignition coil switch I did. Brand new oem plugs gapped to .028 (triple checked using two gap tools). Still no luck........

I finally broke down and disassembled the ignition coils and boots to remove the spring retainers inside the boot. To my surprise the entire middle portion of the spring was filled with what looked like hardened die-electric grease. I thought this was odd so I took a pipe cleaner and cleaned it out with the help of electric connector spray cleaner.

So far I have made 10 back to back WOT pulls to include two hard launches from a stop all the way out to the limiter and up to 107 mph. I said screw it if its gonna blow might as well be today lmao.....

The truck is pulling hard all the way through each gear and all the way up to 107..... Needless to say the truck is performing as it should and I'm glad to have found what seems to be the culprit to my constant misfire issue. Cant wait for my stg2 hardware to go on next week.

Shout out to @wgr73 to being right there through the whole process again. You rock man.....


So good to hear!! And I agree with Stix, great job troubleshooting!! Glad I could help you! Look forward to stage 2 :)
 

sixshooter_45

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Update.....

I couldnt find the culprit regardless of which spark plug/ignition coil switch I did. Brand new oem plugs gapped to .028 (triple checked using two gap tools). Still no luck........

I finally broke down and disassembled the ignition coils and boots to remove the spring retainers inside the boot. To my surprise the entire middle portion of the spring was filled with what looked like hardened die-electric grease. I thought this was odd so I took a pipe cleaner and cleaned it out with the help of electric connector spray cleaner.

So far I have made 10 back to back WOT pulls to include two hard launches from a stop all the way out to the limiter and up to 107 mph. I said screw it if its gonna blow might as well be today lmao.....

The truck is pulling hard all the way through each gear and all the way up to 107..... Needless to say the truck is performing as it should and I'm glad to have found what seems to be the culprit to my constant misfire issue. Cant wait for my stg2 hardware to go on next week.

Shout out to @wgr73 to being right there through the whole process again. You rock man.....

Maybe I missed it in an earlier post but are those the stock coil packs?
 
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rayofsi

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holy crap... i think my truck has the same issue
cylinder 4. replaced plugs, still there.
 
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Misfit_1122

Misfit_1122

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@rayofsi check your coil boot spring retainers...... are you running any type of handheld to clue you into what conditions it's happening under? Increasing load or WOT only?

I have put another 200 miles on so far in varying temps/humidty and rain with nothing but strong performance.

I did pull on the center part of the spring to elong it just a tad to ensure there was plenty of spring tension on both spark plug and ignition coil cap for added peace of mind. But that's just me going a little overboard lol
 

rayofsi

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@rayofsi check your coil boot spring retainers...... are you running any type of handheld to clue you into what conditions it's happening under? Increasing load or WOT only?

I have put another 200 miles on so far in varying temps/humidty and rain with nothing but strong performance.

I did pull on the center part of the spring to elong it just a tad to ensure there was plenty of spring tension on both spark plug and ignition coil cap for added peace of mind. But that's just me going a little overboard lol
happens all around, including idle. too late now, its at a supposedly mod friendly dealership now.
previous shop said possible fuel pump or injectors.
 

smgilles

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happens all around, including idle. too late now, its at a supposedly mod friendly dealership now.
previous shop said possible fuel pump or injectors.

http://www.stratifiedauto.com/blog/misfires-and-the-ecoboost-when-should-you-worry/

I think "misfires" are typical at idle on the 3.5 EB. With my COBB stage 2 I had bad misfires (hesitation, knocking) at WOT. After gapping the colder plugs to 0.026 the WOT misfires resolved. Mine was mostly cylinder #6, which led to me giving the coil pack tear down as well. I still pick up "misfires" but only when idling and if it wasn't for the COBB AP I would not notice them.
 
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