monkonmonk Posted March 17, 2013 Share Posted March 17, 2013 All, Recently I noticed that my car was not reaching full boost from my Infamous Stg2 Tune. This had happened previously but was accompanied by a check engine light. I was informed by this forum and Shamar it was winter/bad gas. I got a new tank of gas clear it and all was well with the world. This time, however, I have no check engine light and no other strange things, noises or the like to accompany my lowered boost levels. I took a learning view when I got home just now and I am hoping someone can shed some light for me. Thanks. MonkLearningView_3-17-2013 4 38 17 PM.csv Link to comment Share on other sites More sharing options...
iNVAR Posted March 18, 2013 Share Posted March 18, 2013 Holy f*ck your car is crying for help badly... stop driving in boost, or even completely if possible and start looking for the cause. I'd start with an intake leak of sorts. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 18, 2013 Author Share Posted March 18, 2013 Checked for leaks, found nothing, but did not do a boost leak check officially with equipment. Can I drive it on no boost at least to get to and from work? Link to comment Share on other sites More sharing options...
iNVAR Posted March 18, 2013 Share Posted March 18, 2013 You probably could baby it, but don't blame me if something blows up. Do a log of your drive while you're at it. How did you check for leaks? Visually? Because that won't tell you anything. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 18, 2013 Author Share Posted March 18, 2013 Visually, tissue paper and the back of my hand is all I have done right now. I can't hear anything strange, the motor is super quiet other than the exhaust at idle. I checked everything along the intake route pre and post turbo. I will look up some sort of procedure for checking intake leaks. If I reset and just let the car idle...if there is an intake leak will the IAM still change? Thanks. Link to comment Share on other sites More sharing options...
fahr_side Posted March 18, 2013 Share Posted March 18, 2013 Oh boy. This is NOT how you look after a modified turbo car. CEL comes on, you find out WHY. From your LV I'd look for leaks, as iNVAR suggested. Just because you find nothing at idle doesn't mean they aren't there. You need to have a proper leak test done at high pressure. There are many tutorials on this process and also for making the test equipment. Any performance shop that works on Subarus should be able to help with this. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 18, 2013 Author Share Posted March 18, 2013 I will build the leak tester and check. Any areas to focus on? Link to comment Share on other sites More sharing options...
Custom Trendz Inc. Posted March 18, 2013 Share Posted March 18, 2013 anywhere and everywhere. Checking mine for leaks tomorrow. Most common area I've read about is the T near the purge valve. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 18, 2013 Author Share Posted March 18, 2013 Oh boy. This is NOT how you look after a modified turbo car. CEL comes on, you find out WHY. From your LV I'd look for leaks, as iNVAR suggested. Just because you find nothing at idle doesn't mean they aren't there. You need to have a proper leak test done at high pressure. There are many tutorials on this process and also for making the test equipment. Any performance shop that works on Subarus should be able to help with this. I did find out about the CEL, and I was informed by this community and my tuner about the bad gas. I had not had a problem since. Yesterday evening I noticed the low boost and stopped driving the car, took a LV and immediately posted due to it not being incorrect. No, I don't understand a lot of the tuning aspects, but I believe i take pretty good car of my modified turbo car. I will build a leak tester today, how much pressure is a high pressure test? Thanks, Monk Link to comment Share on other sites More sharing options...
fahr_side Posted March 18, 2013 Share Posted March 18, 2013 Test to say, 2psi above peak target boost. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
rtbrjason Posted March 18, 2013 Share Posted March 18, 2013 I've seen bad fuel cause some learning views like this as well. Did you recently fill up someplace new or did anyone borrow the car and accidentally put 87 in? How much gas is in it now? Link to comment Share on other sites More sharing options...
spec.B Dream Posted March 18, 2013 Share Posted March 18, 2013 I don't think bad gas is as common as this forum will lead you to believe. If there is nothing wrong mechanically, your tune may need updated. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 18, 2013 Author Share Posted March 18, 2013 rtbrjason, There is about 1/2 tank as of now. I usually have noticed the blip in the past at or around empty (gas light on). spec.B Dream, What would go wrong, or wear, mechanically that would require an update in a tune? All set to do my leak test tonight, should be getting something around 7pm or so. Link to comment Share on other sites More sharing options...
spec.B Dream Posted March 18, 2013 Share Posted March 18, 2013 Leaks are the most common. Also, a dirty MAF could do it. How long was your tune "good"? Was is "good" long enough for you to know it was really good, or has it always had minor issues that have piled up over time? If you took LearningViews daily or weekly for months and never saw a problem, then you can know it was good and something physically changed with your car. If you didn't do that, or didn't log frequently, you may have never actually had a good tune. Sometimes issues take a while to build up before you know there was a problem. FWIW, my Infamous stage 2 tune was never "good". It was good enough to show a clean log immediately after a flash, but over time it would start knocking. I sent wot pulls to Shamer showing the knock, and he claimed it was clutch chatter. I was a newb at the time and didn't push back on this response. Over time, that knock impacted IAM and boost, and by the time I had a local tuner look it over, it was not very happy. Link to comment Share on other sites More sharing options...
fahr_side Posted March 19, 2013 Share Posted March 19, 2013 Dirty MAF usually reads low, meaning you spray more fuel, leading to negative fuel trims. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
spec.B Dream Posted March 19, 2013 Share Posted March 19, 2013 If the MAF reads low, then the ECU sees less air than is actually entering the engine. If there is more air than expected, the front O2 will read lean and add fuel, leading to positive trims. Is there an error in my logic? Link to comment Share on other sites More sharing options...
fahr_side Posted March 19, 2013 Share Posted March 19, 2013 Doh. Blonde moment, carry on. You can check MAFv is the range of 1.00 to 1.70v at idle, or just clean the sensor. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 19, 2013 Author Share Posted March 19, 2013 Spec, I would define good as an average of about 6-8 months before something happens. I will defeinitely make note of this event and start to log more. I did not register it due to the tune because of it happening almost exactly with gas changes here in the great state of Ohio. fahr, I did not find anything with the leaks, but not sure I was doing it right, so I am going to confirm tonight. I will also check MAFv tonight as well and report back. Thanks again guys for all the comments and help. Monk Link to comment Share on other sites More sharing options...
rtbrjason Posted March 19, 2013 Share Posted March 19, 2013 I don't think bad gas is as common as this forum will lead you to believe. If there is nothing wrong mechanically, your tune may need updated. I don't think it's all that common but it has happened to me. If you suddenly see timing being pulled in a large range of cells where there was none before then that's at least a possible culprit. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 20, 2013 Author Share Posted March 20, 2013 Alright, I loaded the system to 5psi and it took roughly 6 seconds to lose 2 psi. After that I loaded it to 10 psi and it took roughly 9 seconds to lose 4 psi. Do I need to go higher? At what pressure do I need to be concerned about the oil fill cap? Thanks for the help. Link to comment Share on other sites More sharing options...
fahr_side Posted March 20, 2013 Share Posted March 20, 2013 You need to go at least 2psi past your peak boost target. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 20, 2013 Author Share Posted March 20, 2013 I will check for max boost tonight. In trying to get RomRaider hooked up to my computer I accidentally reset the ECU and the LV this morning was as if I had just reset it. i had to drive it to work today so I took it easy and stayed out of boost. I did two boost checks on the way to determine the reset, one in Intelligent mode and the other in Sport #. LV taken after completing that, I just wasn't sure if this would show you guys anything else. thanks again. Link to comment Share on other sites More sharing options...
fahr_side Posted March 20, 2013 Share Posted March 20, 2013 Not good. That's quite a big FLKC value, in the most dangerous area. IAM never went to 1.00? Please, stop driving the car until you figure out the root cause. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
monkonmonk Posted March 20, 2013 Author Share Posted March 20, 2013 Nope, never went to one. I will stop driving the car. After the 2psi over max boost test what's next? Link to comment Share on other sites More sharing options...
monkonmonk Posted March 20, 2013 Author Share Posted March 20, 2013 First, I came home after driving my car to work today (sorry fahr side). when I went to take things apart I noticed that I had not tightened the intake to the airbox. Maybe that has something to do with the 2nd bad LV. I don't know but am trying to share everything here. As for the boost leak check. My max boost per Infamous was 18psi. I got right to about 18psi and this happened... See attached of a hard line to rubber hose connection that blew apart and shot oil around all over the place. Additionally, here is a photo of my setup. I have been closing the ball valve when pressure is reached and then counting for bleed off. Oil cap and dipstick are in place. Thoughts now? Thanks again. Link to comment Share on other sites More sharing options...
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