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Old 03-31-2020, 05:05 PM   #1
Robertlolzz
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Default 02 wrx bucking under WOT

Recently started having my wrx buck under WOT. i have gotten the CEL to flash and stay on, but every scanner i have used has shown no codes. has anyone else had this problem?? im on an opensource tune as well and therefore cant use an ap. under normal driving conditions it drives perfectly fine, as well during idle.
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Old 03-31-2020, 05:07 PM   #2
bugeyerex02
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Do you have a tactrix? Do some data logging. That will at least point you in the right direction.

First, and easiest guess is boost leak or exhaust leak.
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Old 03-31-2020, 05:13 PM   #3
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Unfortunately i do not have any way to data log. I'll check around for boost and exhaust leaks. Appreciate the feedback.
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Old 03-31-2020, 05:44 PM   #4
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Quote:
Originally Posted by Robertlolzz View Post
Recently started having my wrx buck under WOT. i have gotten the CEL to flash and stay on, but every scanner i have used has shown no codes. has anyone else had this problem?? im on an opensource tune as well and therefore cant use an ap. under normal driving conditions it drives perfectly fine, as well during idle.
iits probably a misfire. take your coils off and see if there is any discoloration, cracks or such on the coils
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Old 04-01-2020, 10:58 AM   #5
HoosierBuddy
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I've had this issue with bad spark spark plugs.

Phil
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Old 04-01-2020, 11:01 AM   #6
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I'll agree on bad spark plugs, buts isn't it generally unusual to have misfires due to bad coils/plugs and not set codes, particularly at WOT?
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Old 04-01-2020, 01:23 PM   #7
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I'll agree on bad spark plugs, buts isn't it generally unusual to have misfires due to bad coils/plugs and not set codes, particularly at WOT?
had a misfire for about 6 months before it set a code. the way our cars set the code for misfires is there is a certain count it is looking for, so if ti misfires and it doesnt happen often enough, it doesnt trigger the light. just because you dont ahve a code for it doesnt mean its not there
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Old 04-01-2020, 02:50 PM   #8
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aside from the possible misfire, could you also be having a map sensor problem? or a fuel delivery problem?
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Old 04-01-2020, 05:34 PM   #9
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I havenít seen any boost or exhaust leaks yet. I went ahead and ordered new plugs to see if that fixes the issue along with some coil packs. I replaced the fuel pump with a Walbro 255 at around 130k with a new fuel filter as well and Iím at 170k now. Parts wonít be in for another three weeks but Iíll update when I get those put in.
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Old 04-01-2020, 06:06 PM   #10
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Also itís only under load when this happens. Sitting in neutral I can rev up all the way to redline no problem, only during WOT pulls.
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Old 04-02-2020, 05:38 AM   #11
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Quote:
Originally Posted by Robertlolzz View Post
Also itís only under load when this happens. Sitting in neutral I can rev up all the way to redline no problem, only during WOT pulls.
when you get a chance to take out the coils look for discoloration or growths on the coils. that is c clear indication your coils are bad..BTW when was the last time you changed your plugs and coils?
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Old 04-02-2020, 09:40 AM   #12
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Plugs were replaced at 130k, coils havenít been replaced yet that Iím aware of.
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Old 04-02-2020, 08:29 PM   #13
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I took out the plugs and they seemed fine, the coil terminals one of them looks like itís a tad but melted and the others have small brown spots on the same terminal?
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Old 04-02-2020, 08:31 PM   #14
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Same terminal pin I meant, on each coil.
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Old 04-02-2020, 08:53 PM   #15
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Just an FYI.....Flashing CEL is active detonation

That gap looks awful big it should be under 30 thousandths more like 27. Just from your pic its got to be 40k plus. IMO Id ditch the iridiums and get coppers NGK-BKR7E, just change them every 15-20k

Check your motor grounds on the intake manifold ( both sides ) thats where the alot of the sensors and stuff pull ground from.
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Old 04-02-2020, 11:28 PM   #16
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youre looking for discoloration and growths on the other end of the coil
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Old 04-02-2020, 11:39 PM   #17
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I inspected the other ends of the coil as well, didnít see any discoloration or growths either. Thought maybe those spots on the terminals could be the culprit. Iíll check on those intake manifold grounds tomorrow.
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Old 04-03-2020, 12:26 AM   #18
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Iíll also be installing and gapping new plugs at .027 Monday to see if that helps. Iíll update you guys, thanks.
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Old 04-03-2020, 09:07 AM   #19
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That plug does not look good at all, not only the gap but the build color is too dark and looks moist.
A bad coil may not look like anything is wrong, you canít just tell by looking at the coil appearance. If you have 18yo coil packs you should replace them along with new spark plugs.
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Old 04-03-2020, 09:14 AM   #20
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10-4, new plugs and coil packs are going in. Thanks for the advice
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Old 04-03-2020, 11:51 AM   #21
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I don***8217;t think coil packs are needed just yet. If you had a bad coil you would more then likely be getting a random miss all over your RPM not just at high RPM.
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Old 04-05-2020, 04:49 AM   #22
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don't change from the iridiums. just gap them properly coz yours looks like it has large gaps. i've got i only recently changed my iridiums probably 4-6 months ago. i had put in the previous ones in October of 2016!!

i went with a brand called Torch - straight from the East! gapped them and they're doing just fine. they are good tech coz they last very long.

for the coil pack, doesn't look like there's something worth changing. unless the boot is cracked. remove the rubber boot itself and check. yes, you can pull it out and see. and if there's any crack, even a small tear, replace the boot.
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Old 04-05-2020, 05:41 PM   #23
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Iridiums basically just last longer 75-100K they dont give a hotter spark. One step colder iridiums more or less arc better at a shorter gap.

Copper plugs arch hotter but need to be changed more often like 15-25k along with monitoring their gap and taking note of it to know what the best gap is near the spec called for on the engine.
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Old 04-07-2020, 08:53 PM   #24
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Got the new plugs in today, gapíd at .027 and the car runs great now! Thanks for the advice everyone
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