dgoodhue Posted July 27, 2020 Share Posted July 27, 2020 Maybe 2011 is different, but my 2012 reset to 1 when reprogram the Cobb AP OTS tunes. The 1st time I went to the drag strip my DAM dropped to 0.75 just as I got track. I reset programmed my car at the track and it went to 1, I am positive that 2012 defaults to 1.0 with my Cobb AP OTS tune. I had one tank of gas where my DAM would not go back to 1.0, it was constantly 0.75 to 0.812. Except for that one tank full, my car has been 1.0 DAM for all but a maybe 5 miles in the 29k miles I have owned it. I would trying a different top tier gas station that has good volume. Are you using the 15 psi ACN map or the 16 psi 91/92 octane Map? I would try the 16psi MAP. My car had the ACN map when I bought (since it came from CA), but I felt it ran better on the 17psi in normal driving. (It may have been just a placebo affect) Link to comment Share on other sites More sharing options...
Falcor Posted July 27, 2020 Author Share Posted July 27, 2020 I'm running the 91 octane non ACN map. Looking back at pics, it has always been at .812. This was using a few different gas stations. I didn't notice the problem until a couple weeks ago. I checked and the last two tanks were from the same gas station. I have used them before and like that they have the 91 non ethanol option. Also, I unplugged the MAP this morning and drove to work. Log is below. It acted the same except for all the lights on the dash. https://docs.google.com/spreadsheets/d/1n-VoYPUG3JkdoJZKhqbbnD2TLO9YQ7tC_DnJFqz4JoI/edit?usp=sharing Link to comment Share on other sites More sharing options...
Falcor Posted July 27, 2020 Author Share Posted July 27, 2020 Maybe 2011 is different, but my 2012 reset to 1 when reprogram the Cobb AP OTS tunes. If I remember right, the 2010, 2011 is a different tune than the 2012. Link to comment Share on other sites More sharing options...
FLlegacy Posted July 27, 2020 Share Posted July 27, 2020 I've only had a dam lower than 1 a few times for a short period while driving in really heavy traffic on the freeway. I do recall the only way to get the dam up is to go WOT. Link to comment Share on other sites More sharing options...
Falcor Posted July 28, 2020 Author Share Posted July 28, 2020 If I remember right, the 2010, 2011 is a different tune than the 2012. I contacted Cobb and they said DAM should be around 1.0. It’s weird that it is almost always at .812 unless I get on it, and even then it goes back to .812 when restarted. I have a feeling it may be fuel related since the last 2 fill ups were at the same place. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
poconoracing Posted July 28, 2020 Share Posted July 28, 2020 When I was having my DAM issues Ed at XRT had me fill the car where I normally do and add a bottle of Lucas Octane Booster. He wanted to rule out the gas being the issue. We chased it for a while. The issue only presented itself in normal driving, lower rpm and very slight boost (-1psi to +1psi), like staying with traffic at 45pm. The octane boost helped but the issue was still there. Turned out it was a very small boost leak where the intercooler enters the intake. small tear in the rubber flap. I blew the upper one out while tuning and removed it. I should have removed them both. Car was still pushing 19 psi wide open, it seemingly only affected very light boost situations. Took it out and no more DAM drop. Link to comment Share on other sites More sharing options...
Falcor Posted July 28, 2020 Author Share Posted July 28, 2020 I'll have to check that hose. It was replaced by the PO at 60k at the dealer, and it now has 97k on it. The gas light finally came on so I will be filling it up with BP gas today and get some octane booster as well. Link to comment Share on other sites More sharing options...
Falcor Posted July 28, 2020 Author Share Posted July 28, 2020 Filled up with good gas and added the octane booster. Stepped into it getting on the highway and DAM hit .938. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Fabsx Posted July 28, 2020 Share Posted July 28, 2020 Filled up with good gas and added the octane booster. Stepped into it getting on the highway and DAM hit .938. Sent from my iPhone using Tapatalk Keeping closer. Do the reset with the dam relearn procedure and see if it’ll get up to 1 Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Falcor Posted July 29, 2020 Author Share Posted July 29, 2020 I’ll try that again. I wanted to full out a boost leak at the throttle body connector so I removed the rubber ends and put it all back together, no change. The DAM started back over at .812 again and jumped to .875 after going on the test drive. For some reason it always drops back down to .812. That’s not even the part that concerns me. It’s the fact that max boost dropped a couple psi. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Fabsx Posted July 29, 2020 Share Posted July 29, 2020 I’ll try that again. I wanted to full out a boost leak at the throttle body connector so I removed the rubber ends and put it all back together, no change. The DAM started back over at .812 again and jumped to .875 after going on the test drive. For some reason it always drops back down to .812. That’s not even the part that concerns me. It’s the fact that max boost dropped a couple psi. Sent from my iPhone using Tapatalk I might look at the stock map file to see my theory... but I believe if your dam drops or is lower then 1.. the boost will be less then expect to save the motor. Have you check all connections at the turbo? What is your vacuum/boost(ap setting) at idle with ac off. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
poconoracing Posted July 29, 2020 Share Posted July 29, 2020 Looking at your log, I noticed the car is always adding timing when you go +20 throttle. That would track with a vacuum/intake leak. Can you see your long term fuel trims? Link to comment Share on other sites More sharing options...
dgoodhue Posted July 29, 2020 Share Posted July 29, 2020 Looking at your log, I noticed the car is always adding timing when you go +20 throttle. That would track with a vacuum/intake leak. Can you see your long term fuel trims? I noticed as well in his logs that but I am just not sure what is normal. My car is usually at 1, so I don't have a bunch of experience with troubleshooting those issues with Subaru's knock logic. To me the ECU seems like it is proactively looking to reduce DAM. It does seem like the octane boost/gas is reducing the knock counts, but it is not helping very much with the DAM. I would check the intake track for leaks as recommended by others. My suggestion to do after that is to check the grounds make they are all installed and tight. You never know what a mechanic did before. The 5th Gen ground are on both heads going to the frame (you will have to drop the entire plastic under tray to access them, the top starter bolt bracket also has a ground. Link to comment Share on other sites More sharing options...
Falcor Posted July 29, 2020 Author Share Posted July 29, 2020 Thanks for the suggestions. I did get the DAM up to 1.0 today on the way home. Was kinda shocked actually. I do have the log and will post it later. I also contacted Cobb and customer support is helping also. They had me log a pull to check. They didn’t see anything that caught their eye as to why DAM was low. They also suggested trying to run the high wastegate version of the map. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Falcor Posted July 29, 2020 Author Share Posted July 29, 2020 Log from this afternoon: https://docs.google.com/spreadsheets/d/1q8P3xW7FPHty4LlPxNdYGPTsEUZSdZuq7t6RNGX9ZYI/edit?usp=sharing Also, I found the high wastegate map on Cobb's site. Link to comment Share on other sites More sharing options...
poconoracing Posted July 30, 2020 Share Posted July 30, 2020 Can you repost that log with the columns labeled? Link to comment Share on other sites More sharing options...
Falcor Posted July 30, 2020 Author Share Posted July 30, 2020 https://docs.google.com/spreadsheets/d/1AIcpts0D3flURm5nXy5KrBeahh8Ifvoz7JYP__1Nq_E/edit?usp=sharing Link to comment Share on other sites More sharing options...
poconoracing Posted July 30, 2020 Share Posted July 30, 2020 (edited) what gear/speed was this logged at? I pulled out the first knock event logged. It's cylinder 4 (Column L) under light acceleration (E) and slight boost (F&Q) The car is adding fuel (B), but the AFR looks too high to me. I would think under those conditions it would be more in the 13's. The lowest I see is 14.1 when you are letting off the throttle. My thoughts - the car is lean: You either have unmetered air entering the intake (Boost/vaccuum leak), the metering is incorrect (MAF), a fuel delivery issue (bad injector). The car is responding to your O2 sensor by adding fuel like it should. It's just not adding enough. Cylinder 4 is the hottest, so knock shows up there first. I'm going to try to duplicate these and see what kind of readings I get on the cobb. I'll log it for comparison.knockevent.csv Edited July 30, 2020 by poconoracing Link to comment Share on other sites More sharing options...
poconoracing Posted July 30, 2020 Share Posted July 30, 2020 (edited) Here is my crack at logging similar conditions. This is a piece at 1800-2000 RPM in 5th gear. I didn't get the throttle open quite as far, but I got similar boost and RPM My AFR's are in the 12-13's. It looks like your MAF is reading about 10g/s less than mine at similar RPM, trying cleaning it good with MAF cleaner. Hope that gives you somewhere to startBook1.csv Edited July 31, 2020 by poconoracing Link to comment Share on other sites More sharing options...
poconoracing Posted July 30, 2020 Share Posted July 30, 2020 I came across this explanation of fine knock and DAM when I was struggling with my issue. It makes it pretty clear how the system is designed https://www.youtube.com/watch?v=k7oa-EFUIfE Link to comment Share on other sites More sharing options...
Falcor Posted July 31, 2020 Author Share Posted July 31, 2020 what gear/speed was this logged at? 3rd gear. Didn’t check the speed. I’m guessing 25 up to 70ish. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Falcor Posted July 31, 2020 Author Share Posted July 31, 2020 , trying cleaning it good with MAF cleaner. I cleaned the MAF last weekend with CRC. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Falcor Posted July 31, 2020 Author Share Posted July 31, 2020 I am wondering if there is a boost leak somewhere I didn’t see. I sprayed down all the connections I could see with soapy water after I blew into it. This was my rigged up pressure check. I took the air box off and plugged the hole with a 3” test plug. Blew into the piece of clear hose I had and the only leak I found was around the bolt I stuck into the hose. I think the next step would be to get an actual pressure tester with a gauge. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
poconoracing Posted July 31, 2020 Share Posted July 31, 2020 (edited) Just a thought to see if you are indeed chasing unmetered air. Use your Cobb and log Af sense 1 (afr) Af correction 1 (short term fuel trim) Af correction 3 (long term fuel trim) maf (metered air) Rpm Start with the car at operating temp and at idle Slowly increase the rpms to about 3k If the af correction is big at idle, and then gets smaller as you increase rpm, you are chasing a classic intake leak. Note at idle the Maf should read something very near 2.5 g/s Edited July 31, 2020 by poconoracing Link to comment Share on other sites More sharing options...
Falcor Posted August 3, 2020 Author Share Posted August 3, 2020 I sent a few logs from Thursday and Friday to Matt @ Cobb customer service (they have been very helpful along with the forum) and here is what he had to say: Thanks for sending those logs over! It's interesting to see. DAM learns to 1.0, but then there are these random, instant counts of -5.6 Feedback Knock that our logged under partial throttle. I think those instances are what pulls DAM back down to 0.875 and 0.8. At this juncture, it's possible that the knock control sensor could use replacing and/or there's some sort of NVH (loose heatshield or similar) in the engine bay that is creating a noise resembling knock. It may be worth taking a look through to see if anything along those lines may be at play. Sorry I don't have anything utterly specific to point out! Anyone else had a knock sensor go wonky before? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
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