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Discussion Starter #1 (Edited)
B284L 2.8 V6 - Multiple Misfire Codes - Changed 2 Coils - Didn't Fix Issue

Hi all,

I am getting a misfire from my cylinder 6. Looking at the WIS pretty sure that is in the front right (driver side). Can someone confirm this? I just saw someone on the forums say its in the back which somewhat confused me. I just changed the one in the front and my misfire is still misfiring which got me worried wis or my reading of it is wrong.

UPDATE: So I changed both #5 and #6 Coils (Since I picked up 2 just in case), problem didn't go away. I am getting multiple misfires and the engine was running terrible during the test. Car has about 82k on the meter. I changed the plugs a in February because I was occasionally not long after startup the car would hesitate when I was accelerating from a dead stop. The issue somewhat disappeared for the last few months and now I have the misfire issue. Maybe the plugs were not the issue originally. The car did have its #5 coil replaced with a non Bosch one so I figured it might be the issue. But as stated #5 and #6 are both new coils. Still showing misfires in those cylinders. :(

wis - coil number 6.jpg
 

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Looking at the engine from the grill, front bank far right. Closest to the battery.

Sent from my ONEPLUS A5010 using Tapatalk
 

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Looking at the engine from the grill, front bank far right. Closest to the battery.

Sent from my ONEPLUS A5010 using Tapatalk
Yeah, right next to the turbo. Great spot for a coil pack...
 

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Discussion Starter #4 (Edited)
I updated the thread, misfires continue after coil #5 and #6 replaced. Car is running terrible now.

I took a look at the fuel injector area, this looks a bit odd.

IMAG0272.jpg
 

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I updated the thread, misfires continue after coil #5 and #6 replaced. Car is running terrible now.

I took a look at the fuel injector area, this looks a bit odd.

View attachment 252116
What gap are you running on the plugs?
 

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Are those furthest along the rail? How does fuel pressure look?
 

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Discussion Starter #7
New Coils All Around - Misfires Two Days Later

Hi all, :cry:

So I ended up replacing all the coils with new Bosch ones. Replaced all the plugs in Feb with NGK 1959 {#PLFR6C10G} gapped at 0.040 (@Joshinator99) (sticker on the cars front says to gap them at 0.035 - 0.039 so I figured 0.040 would be ok.

Car worked great for 2 days and today again while on the highway I started getting misfires. So plugs, battery, and coils are all new.

@diggs I guess I should check to see what my fuel pressure is at this point. I don't think I can do that with the tech 2 and I have to use a fuel gauge right?
 

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A bigger gap can cause blow-out of the spark. I'd recommend closing the gap to the smallest recommended size.

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Discussion Starter #9
A bigger gap can cause blow-out of the spark. I'd recommend closing the gap to the smallest recommended size.

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I don't think the issue here is the spark plugs. From my understanding the smaller the gap the more possibility of misfire no?
 

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I don't think the issue here is the spark plugs. From my understanding the smaller the gap the more possibility of misfire no?
No, not in this case unless you were getting fouling from a rich fuel condition or excess oil in the cylinders at the time of operation. If you had water/meth injection, I would say taper that down a bit, but I suspect you don't have that.

You exceeded recommended gap already, I'd bring it down.

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x2. Big gaps are a bigger problem with boosted motors and will lead to misfires or blow out. You will want to stay within spec, and starting at the low end of spec will increase reliability as the plug erodes over time and the gap "naturally" widens.
 

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x2. Big gaps are a bigger problem with boosted motors and will lead to misfires or blow out. You will want to stay within spec, and starting at the low end of spec will increase reliability as the plug erodes over time and the gap "naturally" widens.
This. Brian at VTuner had me running 0.80mm (~.0315”) on my ‘11 9-5 Aero plug gap and that worked mint.
 

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Discussion Starter #14
hey guys so i pulled all my plugs and i actually had them gapped at 0.036 which is well within the low end of the spec. after installing everything car started fine and no misfires. but that is exactly what happened last time. i have been reading in a Facebook group how i could be having issues at the wiring harness for the injectors. this puts me in a bind now because the last time i started getting misfires was on the highway and i drove the car below 50 to get home tried to avoid the highway all together. But seeing as the misfires went away after checking the gap on the plugs still at a loss to what's causing the issue
 

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Discussion Starter #15
Given the context, is your fuel pump running ok?

What about injectors?
Using the tech2 and the fuel pump diagnostic test which is a series of pulses and then you check your fuel pressure gauge everything with the fuel pump checked out.

I have not checked the fuel injectors, being that the back injectors are under the intake not sure how I would be able to test that. I will dig into the wis. Being that I am seeing multiple misfires in two cylinders then the rest, I am thinking its further up then the injectors but thats just me thinking out loud.
 
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