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-   -   Troubling problems (misfire in all 4 cylinders) (http://legacygt.com/forums/showthread.php?t=201528)

mmmmspecb 02-12-2013 07:00 AM

Troubling problems (misfire in all 4 cylinders)
 
So I've been having some issues with my Spec B that I could use some help diagnosing.

Background info:
2008 Stage 2 Spec B. 69,000 miles.
CNT catted DP, GS EBC, stage 2 open-source Cryo tune.

About 2 months ago the car started to run like crap. Rough idle, running rich, horrible gas mileage and piss poor driveability. There was a ton of hesitation and it took a ton of throttle to make it get out of its own way.
At that time, I didn't have any Cels and I didn't have a ton of time to work on the car for a month. I thought it may be the A/F sensor failing.

A week ago or so I got a CEL while idling at a red light. I had time to pull the code this weekend and I had misfire codes for all 4 cylinders.

I reset the ECU and the car surprisingly drove like new again, better gas mileage and all but I can tell it is going to get worse as the ecu adjusts.
I pulled a single plug on sunday afternoon and it looked absolutely perfect.


Any idea of what could possibly be my problem? Clogged fuel line? Injectors? I think the fact I had codes for all 4 cylinders rules out a few things. I don't know what else to do at this point. I'll try and get a learning view and some logs when I get time to help diagnose.

KCwagon 02-12-2013 09:09 AM

Have you checked the Oxygen (o2) sensors ?

whitetiger 02-12-2013 09:10 AM

its probably the front o2 sensor

mmmmspecb 02-12-2013 11:57 AM

Quote:

Originally Posted by KCwagon (Post 4290616)
Have you checked the Oxygen (o2) sensors ?

I haven't yet... IIRC I can tell while datalogging based on it's voltage?
I had initially thought it was the front 02 as well, hence why I have one in my possession now. However I never recieved a CEL pertaining to it.

Quote:

Originally Posted by whitetiger (Post 4290619)
its probably the front o2 sensor

Maybe, I have one just in case.

Quote:

Originally Posted by Infamous1 (Post 4290917)
A learning view would help, my guess is a leak. Sounds like your leaning out.

I'll try and get one soon. I would think my IAM is ok since I drove about 30 miles since I reset it.

mmmmspecb 02-12-2013 02:18 PM

If there are any specific parameters anyone things would be beneficial to a log let me know... I'll try and get one in the next few days. Car seems to be running okay today. I seem to be idling rich again. (around 14.2-14.3 on my plx wideband)

cryo 02-12-2013 02:38 PM

+1 on a learning view and avoid driving too much till you get it figured out. If you did generate a leak it will take the ecu time to relearn to compensate as well although with a large leak it normally happens pretty quick.

Dave

mmmmspecb 02-13-2013 06:23 AM

Quote:

Originally Posted by cryo (Post 4291246)
+1 on a learning view and avoid driving too much till you get it figured out. If you did generate a leak it will take the ecu time to relearn to compensate as well although with a large leak it normally happens pretty quick.

Dave

I wish I could avoid driving it :redface: It's my only car and I have to drive frequently with it for work related things... I'll get a LV tonight if possible. The CEL didn't come back yet but it is slowly driving worse and worse again.

xt2005bonbon 02-13-2013 04:41 PM

Quote:

Originally Posted by cryo (Post 4291246)
+1 on a learning view and avoid driving too much till you get it figured out. If you did generate a leak it will take the ecu time to relearn to compensate as well although with a large leak it normally happens pretty quick.

Dave

Probably a dumb question but I still ask: can you get a vacuum leak and still hit max boost?

cryo 02-13-2013 04:53 PM

Yes it is very possible to have a leak and still achieve target boost if the wgdc tables and turbo dynamics will allow.

Keep in mind the ecu doesnt change target boost based on af trims. It has a target and will do everything within its power to achieve boost which includes over working the turbo to get there *ie pumping boost right out a small leak*

Obviously a gross leak will cause you to miss target boost because the lack of ability to build up the total pressure needed.

Hope that helps and answers your question.

Dave

rad.rac3r 02-16-2013 07:34 PM

OP, keep us posted on your findings, im having similar issues. will probably end up doing the same aswell and change my O2 sensors.. Dave's been a great help along the way

mmmmspecb 02-17-2013 05:48 AM

Yea, Dave is awesome. I'm working with him now and I'll post my findings. I'm tired of the car driving like a bag of ass. (and only getting 21 mpgs on the highway sucks)

cryo 02-17-2013 08:19 AM

Quote:

Originally Posted by mmmmspecb (Post 4297833)
Yea, Dave is awesome. I'm working with him now and I'll post my findings. I'm tired of the car driving like a bag of ass. (and only getting 21 mpgs on the highway sucks)

I'm always happy to try and help if I can. For it to drive fine for a year or so and then start acting up definently points twords a leak or something. Shoot me a PM or email with a learning view and we can see what we can do.

Dave

mmmmspecb 02-17-2013 08:39 AM

Quote:

Originally Posted by cryo (Post 4297913)
I'm always happy to try and help if I can. For it to drive fine for a year or so and then start acting up definently points twords a leak or something. Shoot me a PM or email with a learning view and we can see what we can do.

Dave

Yea, exactly.

I'll get you a learning view today. Tune is definitely not the issue.

bnguyenbb6 02-17-2013 12:22 PM

Quote:

Originally Posted by Infamous1 (Post 4290917)
A learning view would help, my guess is a leak. Sounds like your leaning out.

Quote:

Originally Posted by Infamous1 (Post 4291233)
I would hold off logging with misfires on all cylinders and just post a LV.

This. AFR would affect both banks. Either a leak or front o2. Or simple enough, clean your maf sensor. When I ran mine in a blow through set up, it would gunk up with oil and throw misfire codes from running too rich, across both banks.

mmmmspecb 02-18-2013 12:36 PM

MAF sensor was spotless. I'm going to pull the intercooler this coming weekend and see if there are any very visible spots that may be leaking from TB to the turbo.


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