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Old 03-03-2013, 08:13 PM   #1
jonno
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Default 2002 WRX datalog diagnosis

Hi all,

I've got a 2002 WRX with a stage 2 setup:

Catless uppipe and downpipe, with a Clark Turner stage 2 e-tune. If relevant, I've also got a Walbro 255 fuel pump installed.

Now the problem:

During e-tuning we ran into major DAM issues, which I thought I resolved but I'm starting to think I may have only helped a little. My DAM has been dropping randomly and I'm now noticing some knock in a new log I took today. Here is the log:

3/3/2013 DATALOG

I was running out of road (and going uphill) so I didn't get a full 2k to redline at WOT, but hopefully it is enough to see anything that's going on.

Any insights?
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Old 03-04-2013, 08:55 AM   #2
jebjkey
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Boost problems and knock problems, at least fueling looks to be OK based on the AF Learning values.

Your WDC is pretty much maxed out and you are only boosting 15#.
-Check/adjust the WG actuator arm (1/4 turn at a time).
-Check for bad/cracked boost control hoses.
-Check the boost control hoses are setup correctly and connected securely (Cobb's website has an excellent PDF for this).
-When is the last time you checked/changed you air filter?
-AF Learning values are good, so a leak is not likely.

You have knock that is not necessarily showing up in your logs under Fine Learning or Feedback Knock. DAM from 12 to 8 and then again from 14 to 13 later in the pull. Timing does not look unreasonable such that it would be causing excessive knock.
-When is the last time you changed your fuel filter?
-When is the last time you changed your spark plugs?
-Possibly a buildup of carbon (Seafoam?).
-Possibly a buildup of blowby oil in the intake track.
-What kind of fuel are you using?
-Since you do not have a WB, log IDC to get a rough idea of your AFR. With stock injectors you should be close to maxing out IDC on a stage 2 tune. [The stock O2 sensor is useless while boosting. Do not put any value into its reading, only a WB after the turbo will give accurate readings.]
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Old 03-04-2013, 02:11 PM   #3
jonno
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Quote:
Originally Posted by jebjkey View Post
Boost problems and knock problems, at least fueling looks to be OK based on the AF Learning values.

Your WDC is pretty much maxed out and you are only boosting 15#.
-Check/adjust the WG actuator arm (1/4 turn at a time).
-Check for bad/cracked boost control hoses.
-Check the boost control hoses are setup correctly and connected securely (Cobb's website has an excellent PDF for this).
-When is the last time you checked/changed you air filter?
-AF Learning values are good, so a leak is not likely.

You have knock that is not necessarily showing up in your logs under Fine Learning or Feedback Knock. DAM from 12 to 8 and then again from 14 to 13 later in the pull. Timing does not look unreasonable such that it would be causing excessive knock.
-When is the last time you changed your fuel filter?
-When is the last time you changed your spark plugs?
-Possibly a buildup of carbon (Seafoam?).
-Possibly a buildup of blowby oil in the intake track.
-What kind of fuel are you using?
-Since you do not have a WB, log IDC to get a rough idea of your AFR. With stock injectors you should be close to maxing out IDC on a stage 2 tune. [The stock O2 sensor is useless while boosting. Do not put any value into its reading, only a WB after the turbo will give accurate readings.]
Thanks for the thorough reply.

I too had mostly ruled out a leak being at fault, as my AFRs looked pretty good to me, and I had recently replaced my front O2 and gotten rid of some messy AFRs.

I thought it was unusual that DAM was fluctuating without knock showing up in FKL or FKC, is that a typical thing to see?

To address some of your questions:

The e-tune was roughly a month ago, and I did the following just prior to that:
-Fuel filter
-Fuel pump
-Spark plugs (these were changed for one-step colder NGK 2667s gapped at 0.030, as a requirement from Clark for the stage 2 tune. I've had several people on here let me know that this is a dumb idea, but I have kept them based on Clarks reputation and his insistence on them, plus the fact that as far as I can tell, the issue was present before the plug change. Let me know what you think.)
-Seafoamed with ~1/3 bottle through the intake manifold (using Clarks method to ensure that it reaches all four cylinders).
-Full bottle Seafoam through fuel.
-Replaced PCV and the hoses/splitter that attach to it.
-I'm using Shell 93 octane fuel
-My air filter could probably use a change, but it has no more than 6k miles on it. It didn't look too dirty a monthish ago when I checked while doing spark plugs
-Blowby didn't seem excessive to me when I looked in the intercooler while replacing PCV (I also put on new Samco intercooler hoses at this time)
-I've replaced a few boost control hoses, but I may just try and get a whole replacement from the dealer, since the ones that are left are all pretty dry and brittle, but I haven't noticed any that are cracked beyond the ones I've replaced already. The hoses are definitely connected correctly according to Cobbs site. I'll check for how secure they are.
-I'll get some new logs with IDCs logged, and try turning the WG arm.

And as a side corollary to this whole story: I've been struggling with this for many months, most of which I didn't even realize it (bad monitoring on my part). During those months, I've been getting really terrible gas mileage. For a while i was getting 13-15 mpg, and after the O2 sensor replacement I have now been getting no more than 16-18, mostly city driving. This may or may not be related, but someone with more knowledge may be able to tell.

Last edited by jonno; 03-04-2013 at 04:00 PM.
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Old 03-04-2013, 05:02 PM   #4
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Also wanted to add a question about my MAF values. I know it's probably not comparable across cars, but it seems that my MAF values are quite a bit lower than other logs I've read around here. Could this have anything to do with my issues?
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Old 03-04-2013, 11:15 PM   #5
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Quote:
Originally Posted by jonno View Post
Also wanted to add a question about my MAF values. I know it's probably not comparable across cars, but it seems that my MAF values are quite a bit lower than other logs I've read around here. Could this have anything to do with my issues?
For comparison, here is a 3rd gear pull datalog from a completely stock 02 WRX with 93,000 miles on it that my friend owns. I used my AP to datalog and most parameters came out just fine. All parts/sensors are original, but I did clean his MAF sensor before the datalog.


Last edited by jebjkey; 03-05-2013 at 12:12 AM. Reason: added a graph showning your load compared to my friend's stock load
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Old 03-04-2013, 11:38 PM   #6
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Quote:
Originally Posted by jonno View Post
I thought it was unusual that DAM was fluctuating without knock showing up in FKL or FKC, is that a typical thing to see?.
I have not seen this before so I am not sure if it is common or not for an 02 WRX.

Quote:
Originally Posted by jonno View Post
-Spark plugs (these were changed for one-step colder NGK 2667s gapped at 0.030, as a requirement from Clark for the stage 2 tune. I've had several people on here let me know that this is a dumb idea, but I have kept them based on Clarks reputation and his insistence on them, plus the fact that as far as I can tell, the issue was present before the plug change. Let me know what you think.)
I am not sure why he thinks you need one step colder plugs on a 02 WRX stage 2 tune. I can see having one step colder plugs for a stage 3 tune (VF30/34/39/43/48), especially since that makes the plugs the same heat range as a stock STi. Plugs that are too cold will not usually cause knocking problems, that would be plugs that are too hot. So, assuming the plugs are good otherwise, I do not think they are causing any problems.

Quote:
Originally Posted by jonno View Post
-Seafoamed with ~1/3 bottle through the intake manifold (using Clarks method to ensure that it reaches all four cylinders).
-Full bottle Seafoam through fuel.
Maybe try another Seafoam treatment. Did you notice any difference after the first treatment? If you have a lot of buildup it could take more than one cleaning.


The only other thing that comes to mind right now is to check the knock sensor. You would not be the first person to have a worn out/broken knock sensor. Unless there are cracks or something on the sensor it is pretty impossible to see anything wrong with it unfortunately. But if everything else that can be thought of is ruled out, I would replace the sensor.

Have you done a compression test and a leak-down test?
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Old 03-05-2013, 08:28 AM   #7
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Quote:
Originally Posted by jonno View Post
Thanks for the thorough reply.

I too had mostly ruled out a leak being at fault, as my AFRs looked pretty good to me, and I had recently replaced my front O2 and gotten rid of some messy AFRs.

I thought it was unusual that DAM was fluctuating without knock showing up in FKL or FKC, is that a typical thing to see?

To address some of your questions:

The e-tune was roughly a month ago, and I did the following just prior to that:
-Fuel filter
-Fuel pump
-Spark plugs (these were changed for one-step colder NGK 2667s gapped at 0.030, as a requirement from Clark for the stage 2 tune. I've had several people on here let me know that this is a dumb idea, but I have kept them based on Clarks reputation and his insistence on them, plus the fact that as far as I can tell, the issue was present before the plug change. Let me know what you think.)
-Seafoamed with ~1/3 bottle through the intake manifold (using Clarks method to ensure that it reaches all four cylinders).
-Full bottle Seafoam through fuel.
-Replaced PCV and the hoses/splitter that attach to it.
-I'm using Shell 93 octane fuel
-My air filter could probably use a change, but it has no more than 6k miles on it. It didn't look too dirty a monthish ago when I checked while doing spark plugs
-Blowby didn't seem excessive to me when I looked in the intercooler while replacing PCV (I also put on new Samco intercooler hoses at this time)
-I've replaced a few boost control hoses, but I may just try and get a whole replacement from the dealer, since the ones that are left are all pretty dry and brittle, but I haven't noticed any that are cracked beyond the ones I've replaced already. The hoses are definitely connected correctly according to Cobbs site. I'll check for how secure they are.
-I'll get some new logs with IDCs logged, and try turning the WG arm.

And as a side corollary to this whole story: I've been struggling with this for many months, most of which I didn't even realize it (bad monitoring on my part). During those months, I've been getting really terrible gas mileage. For a while i was getting 13-15 mpg, and after the O2 sensor replacement I have now been getting no more than 16-18, mostly city driving. This may or may not be related, but someone with more knowledge may be able to tell.
Hi there.

The DAM enters a learning mode after an ECU reset/reflash or when fine knock learning hits extreme values (at which point the entire fine knock learning table is cleared). What you are seeing at the start of this log is after it has already entered this mode. Once it does, based on certain conditions, it takes a peak at the knock signal and then decreases (knock) or increases (no knock). So, a decreasing DAM in this case is simply a single knock event.

How long had you driven since the last map reflash/ECU reset/car battery disconnect? If you haven't driven through at least a full tank of gas since performing any of those procedures, then you want to give the A/F Learning 1 values more time to populate accurately before determining they are normal.

Other possibilities for unusual knock events include something loose or otherwise rattling on the car whose noise could potentially be transmitted to engine block and picked up by knock sensor (resulting in false knock). Knock sensor itself usually isn't a very common problem unless someone has jacked with it (removed/replaced it at some point and possibly didn't torque or orientate it properly).

Bill
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Old 03-05-2013, 10:47 AM   #8
jonno
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Quote:
Originally Posted by jebjkey View Post
Maybe try another Seafoam treatment. Did you notice any difference after the first treatment? If you have a lot of buildup it could take more than one cleaning.


The only other thing that comes to mind right now is to check the knock sensor. You would not be the first person to have a worn out/broken knock sensor. Unless there are cracks or something on the sensor it is pretty impossible to see anything wrong with it unfortunately. But if everything else that can be thought of is ruled out, I would replace the sensor.

Have you done a compression test and a leak-down test?
I did forget to mention that I had a compression test done with all the previous stuff, and everything came out looking good. I did not have a leak down test though, I didn't think it was necessary if the compression looked good.

I did notice a slight improvement in 'smoothness' after the seafoam. I still have some left, so I can do another treatment. I had been thinking about that, I was just apprehensive because I just put in new plugs directly after the first treatment and had heard it can cause problems with plugs. I'll add it to the list along with checking the knock sensor.

Quote:
Originally Posted by Cobb Tuning View Post
Hi there.

The DAM enters a learning mode after an ECU reset/reflash or when fine knock learning hits extreme values (at which point the entire fine knock learning table is cleared). What you are seeing at the start of this log is after it has already entered this mode. Once it does, based on certain conditions, it takes a peak at the knock signal and then decreases (knock) or increases (no knock). So, a decreasing DAM in this case is simply a single knock event.

How long had you driven since the last map reflash/ECU reset/car battery disconnect? If you haven't driven through at least a full tank of gas since performing any of those procedures, then you want to give the A/F Learning 1 values more time to populate accurately before determining they are normal.

Other possibilities for unusual knock events include something loose or otherwise rattling on the car whose noise could potentially be transmitted to engine block and picked up by knock sensor (resulting in false knock). Knock sensor itself usually isn't a very common problem unless someone has jacked with it (removed/replaced it at some point and possibly didn't torque or orientate it properly).

Bill
Hey Bill, thanks for the reply.

I've gone through around two tanks of gas since the last ECU reset. So this tells me the A/F Learning values should be pretty accurate, but that fine knock learning has seen some extreme values in order for it to enter the learning mode. Should I be staying out of boost and driving carefully at this point? I'd like to get some more logs, but don't want to cause any further damage. As far as loose parts, I've checked around when doing other stuff in the engine bay and nothing seems loose. The only thing I did find when I had the TMIC off a few weeks ago were the three little bolts that hold the hard pipe to the front of the TMIC. They had disappeared a long while ago and I just happened to find them sitting on top of the block right below the intercooler. They could have been rattling around, but that should have been fixed after I got them out of there.

So things I will be doing (in rough order):
- New logs with IDCs (if it's safe to do more logging).
- Adjust wastegate arm (tighten) - associated with this, I do hear what sounds like a decent amount of wastegate flutter during partial throttle.
- Check for loose and rattling heat shields, etc. (running Cobb shield now, it's on there pretty tight).
- Another seafoam treatment.
- Check knock sensor.
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Old 03-05-2013, 08:18 PM   #9
jebjkey
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Do not forget about the manifold heatshields.
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Old 03-05-2013, 09:43 PM   #10
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Originally Posted by jebjkey View Post
Do not forget about the manifold heatshields.
Yep, will check those. I think they were a little loose after my uppipe install.
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Old 03-06-2013, 09:23 AM   #11
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Quote:
Originally Posted by jonno View Post
Hey Bill, thanks for the reply.

I've gone through around two tanks of gas since the last ECU reset. So this tells me the A/F Learning values should be pretty accurate, but that fine knock learning has seen some extreme values in order for it to enter the learning mode. Should I be staying out of boost and driving carefully at this point? I'd like to get some more logs, but don't want to cause any further damage. As far as loose parts, I've checked around when doing other stuff in the engine bay and nothing seems loose. The only thing I did find when I had the TMIC off a few weeks ago were the three little bolts that hold the hard pipe to the front of the TMIC. They had disappeared a long while ago and I just happened to find them sitting on top of the block right below the intercooler. They could have been rattling around, but that should have been fixed after I got them out of there.

So things I will be doing (in rough order):
- New logs with IDCs (if it's safe to do more logging).
- Adjust wastegate arm (tighten) - associated with this, I do hear what sounds like a decent amount of wastegate flutter during partial throttle.
- Check for loose and rattling heat shields, etc. (running Cobb shield now, it's on there pretty tight).
- Another seafoam treatment.
- Check knock sensor.
I would avoid any heavy throttle pulls for now until you diagnose what the issue is.

Bill
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Old 03-06-2013, 01:54 PM   #12
jonno
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Quote:
Originally Posted by Cobb Tuning View Post
I would avoid any heavy throttle pulls for now until you diagnose what the issue is.

Bill
Ok, thanks for the heads up.

I looked over everything I could think of as far as loose and rattling parts and couldn't find anything. Turbo and manifold shields are immovable by hand, so I'm ruling them out.

I'll try tightening the wastegate arm as soon as I can, it may not be until the weekend as I usually work pretty long hours during the week. I'll seafoam it again as well. I also ordered replacements for all boost control lines and connectors between the turbo, inlet, and solenoid. Several of them are pretty dry, so I thought I'd just be safe and replace them all.

Last edited by jonno; 03-06-2013 at 02:14 PM.
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Old 03-06-2013, 02:08 PM   #13
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Quote:
Originally Posted by jebjkey View Post
For comparison, here is a 3rd gear pull datalog from a completely stock 02 WRX with 93,000 miles on it that my friend owns. I used my AP to datalog and most parameters came out just fine. All parts/sensors are original, but I did clean his MAF sensor before the datalog.

This is interesting, thank you. I've got a bit over 92,000 miles, so pretty close to the same as your friends car. Looks like mine is consistently a bit lower but not dramatically. Could this be relevant to the problems I'm having? I may try to pick up a new sensor if I can find one cheap. I'll see if I can find someone to let me try theirs as well.
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Old 03-06-2013, 03:00 PM   #14
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Sorry for spamming this thread, but I wanted to throw in another log. This was taken right after flashing Clarks final map and resetting the ECU, so A/F learning is not going to be accurate. It also includes the parameters Clark wanted, not the defaults. Taken about a month ago.

Since I don't want to do any more WOT logs, I thought I'd through it out there for at least the fact that IDC is logged. This was the last time the ECU was reset, so nothing has changed between this log and the log in the first post other than 2 or 3 tanks of gas. There is an appreciable difference in load readings and MAF readings though. Anything to be gained from that?

DATALOG:
https://docs.google.com/spreadsheet/...0Yld6Tnc#gid=0
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Old 03-07-2013, 08:32 AM   #15
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Quote:
Originally Posted by jonno View Post
Sorry for spamming this thread, but I wanted to throw in another log. This was taken right after flashing Clarks final map and resetting the ECU, so A/F learning is not going to be accurate. It also includes the parameters Clark wanted, not the defaults. Taken about a month ago.

Since I don't want to do any more WOT logs, I thought I'd through it out there for at least the fact that IDC is logged. This was the last time the ECU was reset, so nothing has changed between this log and the log in the first post other than 2 or 3 tanks of gas. There is an appreciable difference in load readings and MAF readings though. Anything to be gained from that?

DATALOG:
https://docs.google.com/spreadsheet/...0Yld6Tnc#gid=0
Load and MAF are a bit higher in this log, but that could just be due to colder temps when the log was taken relative to the other log.

Bill
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Old 03-07-2013, 05:59 PM   #16
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Ok, makes sense. Waiting to hear from a friend about borrowing his MAF to see what it looks like as well.
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Old 03-07-2013, 06:46 PM   #17
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i would most certainly lean towards a bad MAF. 189 g/s peak is just TERRIBLE
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Old 03-09-2013, 07:24 PM   #18
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I'm back after swapping in a different MAF. I borrowed a friends MAF from his 2005 WRX. I don't know that it's even good, but it is a couple years newer. Unfortunately it was probably dirty as well, as the previous owner ran a k&n filter and I don't think it's been cleaned.

Anyway, I could only use it for enough time to do a few logs. I got one WOT log, and a couple city driving logs. Here they are:

WOT immediately after installing MAF and resetting ECU.
City driving, just after returning from WOT run, no ECU reset.
City driving again after resetting ECU.

First thing I noticed is that his MAF doesn't really read any higher than mine did, and maybe even a bit lower. This could be that his is dirty or also going bad, however. My DAM drops quickly in the WOT run, even though nothing is showing up in the feedback knock or fklc columns at that time.


I then reinstalled my own MAF and did a log of city driving (didn't want to do anything WOT):

City driving with my MAF after resetting ECU


These are all immediately after putting in a new OEM air filter as well. Does anyone notice anything in these new logs? ( I apologize for how long some of them are ).
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Old 03-09-2013, 11:29 PM   #19
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The logs are private.
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Old 03-10-2013, 12:13 PM   #20
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I knew I forgot something. They are now visible.
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Old 03-11-2013, 11:11 AM   #21
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Quote:
Originally Posted by jonno View Post
I'm back after swapping in a different MAF. I borrowed a friends MAF from his 2005 WRX. I don't know that it's even good, but it is a couple years newer. Unfortunately it was probably dirty as well, as the previous owner ran a k&n filter and I don't think it's been cleaned.

Anyway, I could only use it for enough time to do a few logs. I got one WOT log, and a couple city driving logs. Here they are:

WOT immediately after installing MAF and resetting ECU.
City driving, just after returning from WOT run, no ECU reset.
City driving again after resetting ECU.

First thing I noticed is that his MAF doesn't really read any higher than mine did, and maybe even a bit lower. This could be that his is dirty or also going bad, however. My DAM drops quickly in the WOT run, even though nothing is showing up in the feedback knock or fklc columns at that time.


I then reinstalled my own MAF and did a log of city driving (didn't want to do anything WOT):

City driving with my MAF after resetting ECU


These are all immediately after putting in a new OEM air filter as well. Does anyone notice anything in these new logs? ( I apologize for how long some of them are ).
When you said you drove through 2 tanks of gas with the previous log (that showed no extreme A/F Learning 1 values) are you sure you did so without relfashing any maps, resetting the ECU or disconnecting the car's battery during that period?

One thing you can try is our off-the-shelf (OTS) stage 2 91ACN map (while still running the 93 octane gas). That is our most conservative map and could tell you if the knock responds to more conservative timing/fuel, indicating that either your local fuel quality is poor, you have a mechanical issue, or your car responds better to a more conservative tune.

Most stage 2 cars will see over 200 g/s MAF if they not at any appreciable altitude and when you are below this (as long as boost is not excessively low), it usually indicates a bad MAF. But, hard to say if the MAF is bad for sure in this case - usually you will see extreme positive A/F Learning 1 when that is the case.

Bill
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Old 03-11-2013, 01:39 PM   #22
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Im fairly certain I didn't reset the ECU or reflash any maps during that time. I definitely didn't disconnect the battery. My memory could be failing me here, so I'll be watching it for a while after my reset on Saturday.

I've been thinking about going back to one of the OTS maps to see what happens. I do know the issue was still present when I was running the 93 version. I'll think about dropping to the 91 version in the future if I don't figure this out soon.

I'm thinking my MAF is at least getting a bit tired, so I went ahead and just ordered a new one. I found an OEM unit for half dealer price, plus I just got my tax return and it's a critical part so what the hell. Now I'm waiting on that and all new boost control lines this week so we'll see what happens with that. Right now my DAM has stayed at 16 since Saturday, but I expect it to drop any day now, as that's what has happened in the past. I've also got a turbo inlet waiting to be installed, so I may put that on in hopes of fixing any leaks that I'm not noticing at least.

I did notice that my A/F Correction 1, while looking at it in live data, will fluctuate pretty wildly. I see it down near -25 and up to +15 or so. It's not being logged right now, would it be helpful to log that and post it?

Last edited by jonno; 03-11-2013 at 01:48 PM.
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Old 03-11-2013, 08:31 PM   #23
Black94Snake
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A/F correction always jumps around, pay more attention to your A/F learning values.
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Old 03-11-2013, 08:40 PM   #24
jonno
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Ok, kind of figured that after reading some more about a/f correction. Thanks.
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