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Discussion Starter · #901 ·
Nice Joebie! It is good to see an update from you again. I went back to the beginning of your thread and looked at the original pics. The newly powder coated rims look great.

I am also really sorry to hear some of what your family has been through.

Looking at the wheels, it looks like you have DBA T3 4000 rotors on there. How do you like them and would you buy them again if you were in the market for new ones now?
Sorry this is late! They are actually the Faction Fab rotors. I'm not entirely sure if I like them yet, they've been ok and the price was ok as well. I also have their pads. I do have something going on when braking but it's possibly related to my rears, which are in rough shape. Been waiting for better weather to rebuild the calipers and replace the rotors. I need to drill/tap the back passenger side bleeder :-| Because they just like the break (No pun intended).

I call the design on the rotors, speedworms LOL
 

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Discussion Starter · #902 ·
Well color me shocked, fuel pump wasn't the issue. But I feel better knowing that yeasty lookin stuff is gone :-D Spark plugs are sub 10k miles so I'm guessing they are fine. Checked cylinder 1 spark plug as it's the easiest and it looks ok from what I can tell. Cylinder roughness all very minor, although 4 does register activity above 18PSI when I'm getting the blow out. Going to need to find some massive motivation to pull that and check.:rolleyes:
 

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I had similar issues a few months ago and it was due to spark plugs. I think the NGKs I put in when I did the motor back in 2020 were fakes from Amazon. Cause I went to Autozone and got 4 new ones and all my problems went away.
 

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Discussion Starter · #906 ·
For the "blowout", do you have a wideband on the car? Thinking if you log AFR you can probably get a good idea of where to start looking for issues...
I do have WB, I meant to switch my PLX gauge to it on the ride home from work but forgot, thankyou for the reminder! I will check tomorrow.

I had similar issues a few months ago and it was due to spark plugs. I think the NGKs I put in when I did the motor back in 2020 were fakes from Amazon. Cause I went to Autozone and got 4 new ones and all my problems went away.
I did check cylinder 4 today, and it appeared mostly OK. I replaced it anyways. I had 2 spare NGKS here, but ordered 4 more and will replace them all this weekend. Cylinder 4 is the hardest anyways and it's now done, so easy peasy on the rest. Also, I have some pictures below and I'm thinking the COP could be on it's last legs. I did notice that Cylinder 4 gap opened up just a tiny bit from .028 to .~030.

What do you mean by “blowing out at high boost levels”? Meaning it does not want to hold boost, or stuttering, or something different?
It feels like spark blowout, so mostly like a stutter. I've had the issue before, and it's been various issues. The last time was fuel pressure related, which is why I attacked it this way this go around.

Posting some pictures below of the Cylinder 4 sparkplug and COP.
 

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Discussion Starter · #907 ·
I noticed the COP isn't looking so great, this is Cyl 4 below. The metal fins are fanned out. Please ignore the oil. 🙃





A f


Sent from my iPhone using Tapatalk
 

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I'd at least clean the contact points off on that coil pack. IDK if it grounds through that bolt but probably best to have clean contact points regardless. If you're getting new coils, then meh.

What I was thinking for wideband is looking to see if you go rich when going into boost, or if you just start seeing lean spikes when it breaks up. In the past, I've seen going rich as a potential boost leak, and random lean spikes when it hiccups as ignition breakup. Reasoning there is given that the sensor reads the presence of oxygen, rich mixtures have little oxygen left after combustion due to excess fuel being present, whereas misfires will leave more oxygen present due to incomplete and/or no combustion.

My experiences was with a failing coil on another platform. I ended up having to gap the plugs way down compared to what other people ran. As I had to gap closer and closer, I tried another coil for the heck of it and issue solved. But again, if you are just replacing the coils ( I would if it were my car just based on appearance, and then worst case I have some spares for troubleshooting. haha), then that probably isolates ignition issues.
 

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Spark blowout does happen. One step colder spark plugs also dont tend to last as long from my experience. I would imagine on E85, the life span may be less. My first set of one step colder plugs was good for about 30K without issue. My last set lasted roughly 20K before I got spark blowout under boost. When I pulled them, I found that my gaps had widened up to and over .035. Mind you my sti is daily driver, on pump fuel, pushing 20psi. I had the same issue with my ignition coils as well. Passenger side coils for cyl 1 and 3 were getting pretty rusty and appreared to be starting to come apart, so I replaced all 4. I decided to keep my spark plug intervals to 20K. I think maybe next time when I change them out, I may reduce my gap to .028 on the new ones and see how it goes.

 

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i really should look at how long mine last, i feel like i replace plugs so much that idk the intervals. most the time i'm prepping for the track and like, well, may as well swap these lol. half the time they are still good and i'm swapping them for new plugs.
 

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Discussion Starter · #912 ·
I run way tight gaps so I have to swap them out about every 10k. 0.022 spark plug gaps.

Will notice blowout around .025 to .027 at higher boost levels.
Very interesting, I'm running .028 on 2309's and have had very minimal issues overall. (Peak 30PSI) I wonder if elevation has some part in the need for smaller gaps. I just rolled over 10k on these, and they haven't been easy miles that's for sure.


I'd at least clean the contact points off on that coil pack. IDK if it grounds through that bolt but probably best to have clean contact points regardless. If you're getting new coils, then meh.

What I was thinking for wideband is looking to see if you go rich when going into boost, or if you just start seeing lean spikes when it breaks up. In the past, I've seen going rich as a potential boost leak, and random lean spikes when it hiccups as ignition breakup. Reasoning there is given that the sensor reads the presence of oxygen, rich mixtures have little oxygen left after combustion due to excess fuel being present, whereas misfires will leave more oxygen present due to incomplete and/or no combustion.

My experiences was with a failing coil on another platform. I ended up having to gap the plugs way down compared to what other people ran. As I had to gap closer and closer, I tried another coil for the heck of it and issue solved. But again, if you are just replacing the coils ( I would if it were my car just based on appearance, and then worst case I have some spares for troubleshooting. haha), then that probably isolates ignition issues.
Absolutely makes sense, what I realized the other day is I can not possibly watch AFR while I'm WOT :-D That being said, I was able to replace cylinder 4 spark plug and the issue hasn't completely gone away, but is miles better than it was. Replacing all plugs this weekend. Heavily debating COP's too. My AP tune was supposed to incorporate my AFR input however... someone missed that when tuning. :-|

Spark blowout does happen. One step colder spark plugs also dont tend to last as long from my experience. I would imagine on E85, the life span may be less. My first set of one step colder plugs was good for about 30K without issue. My last set lasted roughly 20K before I got spark blowout under boost. When I pulled them, I found that my gaps had widened up to and over .035. Mind you my sti is daily driver, on pump fuel, pushing 20psi. I had the same issue with my ignition coils as well. Passenger side coils for cyl 1 and 3 were getting pretty rusty and appreared to be starting to come apart, so I replaced all 4. I decided to keep my spark plug intervals to 20K. I think maybe next time when I change them out, I may reduce my gap to .028 on the new ones and see how it goes.

I've had decent success with .028, it's been the only gap I've run for the last 47k miles at these power levels. I do notice after time, the plugs open up a bit as well. I only verified Cyl 1 and 4. 1 was ~.028 and 4 was probably ~.03001 just a hair over .030. I'll know the condition of the rest this weekend when I pull them. Also leaning toward replacing the coils as well, I have over 100k on them now and over half those miles have been at higher power levels to varying degrees.


So I didn't even think about this until now, but actually have most of this documented(mostly) - The anomalies here being the 17k and 28k run... not sure how that's possible but buying history confirms it. All other changes were around 10K ...weird. I supposed it's possible the COP's are tired, though most of what I've read says they're either working or they're not.
Mileage:Notes:Mileage on Plugs at time of change:
April 2016
45,054​
Motor new/Sparkplugs new - Pump Gas tune only
9,442​
October 2016
54,496​
E85 tune - I feel like I replaced plugs for this, but I don't have it written down :-| Amazon history shows I bought 4 NGK's in Aug 2016, so let's assume I did replace them for this tuning session. 8,342
June 2017
62,838​
New spark plugs
17,784​
August 2019
91,035​
New spark plugs
28,197​
March 2022
~102,000​
New Spark plugs(Yet to be done)
10,965​
 

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Absolutely makes sense, what I realized the other day is I can not possibly watch AFR while I'm WOT :-D That being said, I was able to replace cylinder 4 spark plug and the issue hasn't completely gone away, but is miles better than it was. Replacing all plugs this weekend. Heavily debating COP's too. My AP tune was supposed to incorporate my AFR input however... someone missed that when tuning. :-|
In the past, I've used EvoScan and IIRC I just fed the signal from my PLX wideband into a port on the ECU and it was picked up. This was on an evo, but it looks like you can do similar on these cars and just use the accessport to log. I'd make sure to read that whole thread as it appears there are some gotchas.
 

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Discussion Starter · #916 ·
UGH I legit just got my spark plugs from Amazon 🙃 I was looking at something the other day, and it had awesome reviews, I started reading them and none of the reviews were for the product I was looking at. So I think the game is, you change the product listing, but keep the old reviews or something. Shit's wild. Can't believe they let that kind of stuff go on.

So I'm currently pulling the plugs, 1 - 3 look ok. But Cyl 1 COP looks rough, like Cyl4's did. I was on the fence before, but I'm for sure replacing all of them at this point. Should I go OEM or OTL? Seems like OEM are slightly more money. The only real reviews I could find on the OTL's is on IIR's website.
 

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Discussion Starter · #917 ·
In the past, I've used EvoScan and IIRC I just fed the signal from my PLX wideband into a port on the ECU and it was picked up. This was on an evo, but it looks like you can do similar on these cars and just use the accessport to log. I'd make sure to read that whole thread as it appears there are some gotchas.
When Cobb added the flex fuel functionality into the AP, they actually free'd up some inputs for datalogging 2 separate non ECU related sensors. The functionality had to be enabled though. Ofcourse, I paid for the class so I could get access to the tuning suite, I just never did the class :-D
 

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Discussion Starter · #918 ·
Finally replaced all the COP's, didn't test drive yet because I started down the rabbit hole of trying to fix the endlink clunk which only showed up late last year.

I have this feeling the issue won't be resolved and next up will be TGV/Manifold gaskets. Joy.
 

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Discussion Starter · #919 ·
Annnnnd the verdict is back... COP's was it. Got a nice pull in yesterday which was confirmation. Honestly kind of surprised because this is not typical of COP's from everything I've read. Onto the next issue I suppose, it is a Subaru afterall. :LOL:
 
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