Rough idle in cylinders 2 and 3

[DrowningT]

I was hoping someone would help me figure out my rough idle issue. The CELs have popped up for the two cylinders and when it first happened (lean in bank one) but that was a couple months ago. Long story short after finally arriving home from purchasing I quickly found out it was the blue tee behind the TMIC, so I replaced it with a much better version that won't slip off. Ever since it's had a rough idle, I've replaced the plugs with the correct iridium plugs and I replaced a gasket that was missing off the BOV. I've done a smoke test and couldn't find anything past that. I'll be testing the OCV through ROMRAIDER and watching it, I'm thinking it might be either the OCVs, turbo inlet, or the intake manifold gaskets. Any help would be appreciated, the car is completely stock as of now, banjo bolts look to of been removed and I plan on installing a NVIDIA up pipe in the next two weeks.

 

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[relative4]

Fuel trims, misfire counts? LV would be great.

Invidia UP is poopoo, much better off with a used STi or another high-quality flex unit.

[DrowningT]

I will upload my findings when I get home, off memory however off memory the OCVs looked to be operating correctly. I'll have to install LV and run it and see how everything looks (still a bit new at data logging), the roughness count got all the way to 9 in cylinder 2 and I believe 6 or 7 in cylinder 3. Cylinder 4 also had one come up, but the car also stalled on me on the way home last night, as for the NVIDIA up pipe, I got it for a decent price never used so I'm fine with it.

 

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[relative4]

as for the NVIDIA up pipe, I got it for a decent price never used so I'm fine with it.

 

That's how I got mine. Once I found a bolt to plug the EGT bung that had the wrong thread pattern, I installed it; was never able to seal the flange leak. They have the angle wrong. Finally replaced with a used STi, all fixed. If you want to do the job twice, by all means install the Invidia.

[DrowningT]

 

here is the ltv of it currently at idle, ive been watching the fuel correction as well, a/f correction #3 16 bit is reading up to -69% which seems like alot (again still new to this but i believe that should be less) engine speed periodically drops to 400 and some change in RPM and actually stalled while idling, roughness monitors have read

cyl #1 0

cyl #2 6

cyl #3 10

cyl #4 2

It has thrown a code every now and again but hasn't since yesterday but it did stall on me when driving home today, when moving at higher RPMs it drives just fine.

 

MAF is reading as low as 1.5 g/s and high as 11.5 g/s

and A/F sensor is reading about 15

all are at idle operation, if more info in needed to help let me know and ill get it when I can. As always, any help is much appreciated.

romraiderlog_20180814_171745.csv

[relative4]

Have you swapped coils and/or injectors from the misfiring cylinders to other cylinders?

The low IAM with no timing pulls seems strange... how did you smoke test?

[DrowningT]

I haven't swapped coils yet and planned on swapping cylinder 1 and 2 to see what happens, if that doesn't do anything then I'll swap the injectors as well. I smoke tested with a smoke machine that my buddy had at work, I set it through the vacuum hose connected to the BOV and stopped when I saw the smoke coming through the intake, I probably should of waited a little longer just to confirm. Oh well, ill just stick a can in the intake tube and blow into the hose off the BOV and see if I can't hear a leak somewhere.

 

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[relative4]

If you don't seal the system, you can't build the 1-2 PSI needed for a valid smoke test. Re-do. If getting access to that machine is difficult, you can buy on on eBay for $65.

Anyway, swapping to fix the misfires is step 1.