Jiyujin Posted November 7, 2016 Share Posted November 7, 2016 Greetings from Oz, I would like to ask some of you long-time experienced members for any help or assistance in solving this mystery. To cut a long story short, I'm having ongoing idle bounce and flat spot or hesitation issues for a while now and can't seems to find what's causing these problems. The car gets driven once or twice a week and barely does 10,000 kms a year. I put in Subaru injector cleaner once every 6 months and it gets serviced 3 times a year. It's a running a Raptor Supercharger (7psi boost) on a stock 2.5 (AUDM) with a 4EAT, and Omni 3 bar MAP sensor. These problems are intermittent and would happen when the engine is cold or hot when accelerating from a stop. On some hot or cold days the car would be perfect but on other days it would be a pain to drive. I'm running 95 from my local BP and have been for the last 2 years since I've had the car. What I have replaced in the past 12 months of the top of my head, there may be something that I've missed though... 1. New DW fuel pump and in-tank filter. (Replaced the fuel pump - similar flow) 2. New (3rd set) spark plugs. 3. New (2nd set) Pink Sti injectors. 4. New (3rd one) 02 oxygen sensor. 5. New Apexi air filter. 6. New BOV. 7. New (3rd one) MAF. 8. New SC belt. 9. New water reservoir. 10. New Fuel pressure damper 11. Replaced ignition coil 12. Replaced throttle body 13. Replaced ignition leads I'm out of ideas so any constructive advice is greatly appreciated! Cheers!! Update: Replaced the fuel pump a few days ago. Installed a new fuel pressure damper. I've cleaned the throttle body several months ago but it made no difference so replaced it. I was told by my tuner that it is fuel related. I have had it checked for vacuum leaks, no problem there. I've installed another tested set of injectors (same flow rate) to check if they were the cause of the idle bounce, no change. Used a can of Upper Engine cleaner to give it another clean, but no change. Link to comment Share on other sites More sharing options...
RustyRuu Posted November 7, 2016 Share Posted November 7, 2016 have you cleaned your IACV (idle air control valve) or replaced it Link to comment Share on other sites More sharing options...
Jiyujin Posted November 7, 2016 Author Share Posted November 7, 2016 have you cleaned your IACV (idle air control valve) or replaced it Thanks for the reply RustyRuu! I've cleaned the throttle body several months ago but it made no difference. My model has drive by wire, which is basically built in to the system. Cheers mate! Link to comment Share on other sites More sharing options...
GEE-OTTO Posted November 7, 2016 Share Posted November 7, 2016 What map are you running with the raptor SC kit? I know they give you a base map but did you ever get it tuned properly? Link to comment Share on other sites More sharing options...
Jiyujin Posted November 7, 2016 Author Share Posted November 7, 2016 What map are you running with the raptor SC kit? I know they give you a base map but did you ever get it tuned properly? Hey GEE-OTTO, Custom map, I have a tuner (overseas) who has been working on it since the Raptor SC was installed. He has told me that it is fuel related so looking along the lines of what may be causing it. I may look at the fuel pump again. Cheers! Link to comment Share on other sites More sharing options...
RustyRuu Posted November 7, 2016 Share Posted November 7, 2016 Have you checked for any vacuum leaks yet? Link to comment Share on other sites More sharing options...
Jiyujin Posted November 8, 2016 Author Share Posted November 8, 2016 Have you checked for any vacuum leaks yet? Yes, have checked for vacuum leaks. All good! Link to comment Share on other sites More sharing options...
GEE-OTTO Posted November 8, 2016 Share Posted November 8, 2016 I think the problem with the 04 AU (which is the early 05 US 2.5is) is that the fuel line routing is different. IIRC there isnt a return ine or the sizing on the line and pump combo present issues. There was a user on here that tried to run a turbo on a early 05 and it never ran correctly and it was due to the lack of a return line. Link to comment Share on other sites More sharing options...
Jiyujin Posted November 8, 2016 Author Share Posted November 8, 2016 I think the problem with the 04 AU (which is the early 05 US 2.5is) is that the fuel line routing is different. IIRC there isnt a return ine or the sizing on the line and pump combo present issues. There was a user on here that tried to run a turbo on a early 05 and it never ran correctly and it was due to the lack of a return line. Hey GEE-OTTO, Mine is a MY08 and am unaware of the line issue. I'm going to replace the fuel pump and fuel pressure regulator and see how she goes. Will give you an update once these have been replaced. Cheers! Link to comment Share on other sites More sharing options...
GEE-OTTO Posted November 8, 2016 Share Posted November 8, 2016 Yeah I couldnt tell which year you had but I remembered that. Yeah the intake filter could be clogged the pump and/or FPR could be faulty the 08 shouldnt have any fuel line issues at all if you can use a WRX/LGT FPR when you swap pumps. Link to comment Share on other sites More sharing options...
rossotron Posted November 12, 2016 Share Posted November 12, 2016 If it's drive by wire, go to a Subaru dealer and check to make sure your throttle body is not faulty. Link to comment Share on other sites More sharing options...
bomberlegacy Posted November 18, 2016 Share Posted November 18, 2016 Who is doing your tuning?(curious) My raptor setup always idled smoothly and with good tip-in fueling tuning, it had no hesitation. Do you have a wideband to see your afr? With all those new parts(aside from the fpr), I don't see how it could be a mechanical problem. '08 Legacy 2.5i - hybrid intake - delta 1000 - E85 - magnaflow exhaust Link to comment Share on other sites More sharing options...
Jiyujin Posted November 21, 2016 Author Share Posted November 21, 2016 Who is doing your tuning?(curious) My raptor setup always idled smoothly and with good tip-in fueling tuning, it had no hesitation. Do you have a wideband to see your afr? With all those new parts(aside from the fpr), I don't see how it could be a mechanical problem. Hey mate, I would rather not say at this time...glad to hear yours is running smoothly. But, a new fuel pump went in a few days ago and it made no difference. Issues are still occurring. There is no fuel pressure regulator on AUDM but there are fuel dampers on the fuel line. Will replace the main one that is in the engine bay in the next day or two to see how she goes. Will also check the air fuel ratio. Cheers! Link to comment Share on other sites More sharing options...
Tuning Alliance Posted November 21, 2016 Share Posted November 21, 2016 Giovanni? -Brian Contact us for all your tuning and performance parts needs! Etuning the legacy community since 2008! Follow us on FACEBOOK | INSTAGRAM [sIGPIC][/sIGPIC] Link to comment Share on other sites More sharing options...
Jiyujin Posted November 24, 2016 Author Share Posted November 24, 2016 Giovanni? -Brian Sorry, have no idea who he is. Anyway, I replaced the fuel pressure damper and it made a slight difference. There is still an idle bounce during warm up and also hesitation once the engine is at running temperature. Am at a loss now .... Link to comment Share on other sites More sharing options...
RustyRuu Posted November 27, 2016 Share Posted November 27, 2016 IACV, have you looked into that at all or cleaned it? Link to comment Share on other sites More sharing options...
Jiyujin Posted November 29, 2016 Author Share Posted November 29, 2016 IACV, have you looked into that at all or cleaned it? Hey RustyRuu, Yes, have had it cleaned, but will have it checked next week. Cheers! Link to comment Share on other sites More sharing options...
Jiyujin Posted December 1, 2016 Author Share Posted December 1, 2016 I had some free time this week so I decided to remove the throttle body. Looking at it there was carbon build up on the inside so I decided to swapped over a newer unit which I had here. After warming up the engine, the idle bounce returned within 5 minutes. The flat spot/hesitation also returned....the change over made no difference. I'm not sure what to look at next... http://i1371.photobucket.com/albums/ag310/jiyujin/Throttle_Body_zpsgtzcx0px.jpg Link to comment Share on other sites More sharing options...
Jiyujin Posted December 2, 2016 Author Share Posted December 2, 2016 https://www.facebook.com/jiyu.jin.796/videos/657219734455771/ Here is a video of the idling. This is about 10 minutes into the warm up stage. Sorry, you may need to log into your Facebook account to view it. Will check it out later. Link to comment Share on other sites More sharing options...
bomberlegacy Posted December 2, 2016 Share Posted December 2, 2016 Can't view the video What injectors are you using? I'm curious to see your AFR and MAF readings during idle, although issues with that should be easy for a tuner to identify '08 Legacy 2.5i - hybrid intake - delta 1000 - E85 - magnaflow exhaust Link to comment Share on other sites More sharing options...
Jiyujin Posted December 2, 2016 Author Share Posted December 2, 2016 Can't view the video What injectors are you using? I'm curious to see your AFR and MAF readings during idle, although issues with that should be easy for a tuner to identify Hey Bomberlegacy, I'm using pink sti injectors, actually my 2nd set. I may try the blue GT injectors as I have borrowed a set from a friend. Here you go....sorry not a good pic. I'm still trying to learn the numbers on the tuning side of things. Cheers! http://i1371.photobucket.com/albums/ag310/jiyujin/Idle_zpsm5gvpi9y.jpg Link to comment Share on other sites More sharing options...
bomberlegacy Posted December 2, 2016 Share Posted December 2, 2016 Does the AFR jump around or stay steady while the idle is bouncing around? Oh.. One more thing .. can you post a pic of your engine? More on the SC side '08 Legacy 2.5i - hybrid intake - delta 1000 - E85 - magnaflow exhaust Link to comment Share on other sites More sharing options...
Jiyujin Posted December 2, 2016 Author Share Posted December 2, 2016 Does the AFR jump around or stay steady while the idle is bouncing around? Oh.. One more thing .. can you post a pic of your engine? More on the SC side The AFR does fluctuate with the idling when it starts to bounce. Will check the plugs but it feels like the timing or the afr.... http://i1371.photobucket.com/albums/ag310/jiyujin/2.5SC_zpsuhktg2yl.jpg Link to comment Share on other sites More sharing options...
bomberlegacy Posted December 3, 2016 Share Posted December 3, 2016 Nice. Where is your bov tube routed? Do you have any more pics of the pre-SC intake? (Just curious, comparing to mine) '08 Legacy 2.5i - hybrid intake - delta 1000 - E85 - magnaflow exhaust Link to comment Share on other sites More sharing options...
Jiyujin Posted December 3, 2016 Author Share Posted December 3, 2016 Nice. Where is your bov tube routed? Do you have any more pics of the pre-SC intake? (Just curious, comparing to mine) Cheers mate! The bov tube runs down to the air filter bracket just behind the headlight which makes it much quieter. Here is another pic but it's not very clear, sorry! Changed the spark plugs today but made it no difference... http://i1371.photobucket.com/albums/ag310/jiyujin/2.5SC_2_zpsasrhpgvp.jpg Link to comment Share on other sites More sharing options...
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