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Old 12-09-2019, 12:42 AM   #1
Robert428
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2006 WRX STi
Mikey Tuned

Default Fluctuating Cylinder Roughness

Any thoughts on why my cylinder roughness is fluctuating?

On the accessport cylinder 1 and 2 would go extremely high and then go back to 0 and it repeats the process.

Iíve done a boost leak test, had injectors cleaned, put new ngk 2309 plugs again, swapped my coil packs with another set I had laying around. Issues still stayed the same.

When I tap the accelerator the car stumbles and dies.

Mods: -brand new outfront closed deck long block
(just installed)
- ets 6870 kit
- id2000cc
- speed density kit
-all the goodies.

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Old 12-09-2019, 11:03 AM   #2
subydude
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New tune to go with all that?
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Old 12-09-2019, 11:13 AM   #3
Robert428
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Quote:
Originally Posted by subydude View Post
New tune to go with all that?


Yupp, my car was tuned by JR on the exact same setup so Iím using the same tune. I didnít make any changes to mods. Motor was just refreshed
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Old 12-09-2019, 06:29 PM   #4
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1) check engine grounds, make sure they are clean, and tight and none missing.
2) check the pins on the coil packs and coil pack connectors to make sure they are free of corrosion, dirt and general grime.
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Old 12-09-2019, 07:50 PM   #5
Robert428
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Quote:
Originally Posted by Turn in Concepts View Post
1) check engine grounds, make sure they are clean, and tight and none missing.
2) check the pins on the coil packs and coil pack connectors to make sure they are free of corrosion, dirt and general grime.


Yes engine grounds are in good condition, even added a few more to the engine to the chassis.

Coil pack connectors are perfect, no cracks or debris.
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Old 12-09-2019, 07:53 PM   #6
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Quote:
Originally Posted by Robert428 View Post
Yes engine grounds are in good condition, even added a few more to the engine to the chassis.

Coil pack connectors are perfect, no cracks or debris.
Ok. I'll admit then that I'm a bit stumped.
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Old 12-09-2019, 08:29 PM   #7
Robert428
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Quote:
Originally Posted by Turn in Concepts View Post
Ok. I'll admit then that I'm a bit stumped.
yeah so am i, this is confusing me. I had my id2000's cleaned and flow tested, changed all plugs again with ngk 2309, swapped out my coil packs with another OEM set i had, did a boost leak test, and i did a leakdown test before i installed this motor. I never had this issue before with my previous builds, i tried different base maps i have and roughness is still fluctuating like crazy.

I'm going to change out the engine harness, front O2, crank sensor, cam sensors, knock sensor, drain fuel tank, and new plugs again.

At least i know something is still working properly, the shift linkage bushings and pivot bushings i got from you guys a few years ago
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Old 12-10-2019, 11:26 AM   #8
subydude
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Can you actually feel/hear the misfire when it's fluttering?
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Old 12-10-2019, 11:54 AM   #9
Robert428
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Quote:
Originally Posted by subydude View Post
Can you actually feel/hear the misfire when it's fluttering?


Yes the car wants to die when you tap the accelerator, and it has a slight vibration at idle
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Old 12-10-2019, 12:39 PM   #10
Delphi
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Is your timing out? Crank and Cam sensors okay?
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Old 12-10-2019, 01:09 PM   #11
subydude
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Timing belt being off is a good next check. Swapping sensors is easier, but generally if you're re-using sensors that were good before it's unlikely they've gone bad.
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Old 12-10-2019, 02:21 PM   #12
subaru_gc8
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did you ask Jr?
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Old 12-10-2019, 06:43 PM   #13
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Long shot, but make sure none of the plugs were cracked during install. yeah yeah yeah, but I've seen it before.
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Old 12-15-2019, 12:12 AM   #14
SCOOBYROO 05
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Quote:
Originally Posted by Robert428 View Post
Any thoughts on why my cylinder roughness is fluctuating?

On the accessport cylinder 1 and 2 would go extremely high and then go back to 0 and it repeats the process.

Iíve done a boost leak test, had injectors cleaned, put new ngk 2309 plugs again, swapped my coil packs with another set I had laying around. Issues still stayed the same.

When I tap the accelerator the car stumbles and dies.

Mods: -brand new outfront closed deck long block
(just installed)
- ets 6870 kit
- id2000cc
- speed density kit
-all the goodies.

Sounds like itís time for a leak down test.
How are your fuel trims? If you are pulling a lot of fuel I would suspect some tight valves.
That all being said if the calibration was on before the refresh

Were the heads built? Was the lash checked after the heads were torqued to the block?

Last edited by SCOOBYROO 05; 12-15-2019 at 12:13 AM. Reason: Spelling
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Old 12-16-2019, 07:30 PM   #15
Robert428
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2006 WRX STi
Mikey Tuned

Default

The long block was assembled by Outfront Motorsports. Spoke to them about the issue and really didnít have much to say...
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Old 12-17-2019, 09:30 AM   #16
Paul
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Twin Scroll 2.5XTR EJ207

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Quote:
Originally Posted by SCOOBYROO 05 View Post
Sounds like itís time for a leak down test.
Yea unfortunately if everything else checks out Iíd be doing a compression and leak down test before throwing any more money at it. If itís something internal that will let you know.
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Old 12-17-2019, 04:11 PM   #17
BlackFighter
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RalliSpec Shortblock

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Quote:
Spoke to them about the issue and really didn’t have much to say...

Really? You bought a brand new block from them, and now have issues with it and they didn't have much to say? I would expect them to try their best to help with this issue, its their block and their reputation.

Like everyone else said leak down test, compression test, try putting a mini cam in the spark plug hole and try to see whats going on in there, or try a oscilloscope.

Do you have a lightened flywheel by any chance? I seem to recall reading on here several cases where a lightened flywheel causes roughness or misfires at idle. Just a thought. Also remember a buddy of mine had the same issue and he said when the cam's were changed, one of the spacers on a valve was a little off, and would never completely close. What kind of cams came with the long block?

See if this helps
https://www.clubwrx.net/threads/if-y...his.134337553/

Last edited by BlackFighter; 12-17-2019 at 04:25 PM.
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