Scoobiidoo Posted February 18, 2019 Share Posted February 18, 2019 To start, this is on stock tune. Replaced all vacuum hoses yesterday including all 4 of the vent hoses and throttle body hose. Checked with soapy water and looks fine. Replaced MAF and realized PO has a non oem paper air filter in the airbox. Reset ecu and did the idle relearning process. Now it idles rich with +ve AF corrections and AF learning. When driving with gradual buildup into boost the AF is pegged at stoich +-0.1. Going up a good incline holding speed with boost creeping up into 3-4 psi and the AF is still at stoich. The attached log was from sitting at the traffic light and just gradually accelerating. Could my O2 sensor be going bad? Fuel pressure regulator? Or the non oem air filter? ThanksBtSsm_20190217_183755.csv Link to comment Share on other sites More sharing options...
relative4 Posted February 18, 2019 Share Posted February 18, 2019 You're not idling rich. You're idling moderately lean, and going extremely lean at higher ranges. When attempting to boost, you are getting absolutely no boost. Sounds like you have a badly torn turbo inlet and/or badly split intercooler, and/or other severe vacuum/boost leaks. Link to comment Share on other sites More sharing options...
Scoobiidoo Posted February 18, 2019 Author Share Posted February 18, 2019 You're not idling rich. You're idling moderately lean, and going extremely lean at higher ranges. When attempting to boost, you are getting absolutely no boost. Sounds like you have a badly torn turbo inlet and/or badly split intercooler, and/or other severe vacuum/boost leaks. Idling at 14.2 AFR is moderately lean?? What are you guys idling at? Previously before all hose replacements, my idle was at 14.7 AFR solid the whole time with positive fuel corrections and learning. The highest AFR when boost was in the 0-2 psi range was 14.6 AFR which is almost stoich and not lean. I should add that the log was taken with gradual acceleration and not WOT. At WOT it will give me 11.1 AFR. If it goes to open loop it will enrich. The intercooler has been "bulletproofed". I haven't checked the turbo inlet hose yet as this is the prep work for upgrading to the VF52. Figure I will wait till when I get the turbo off. The stock turbo doesn't make any noise and looks fine when peeking down the turbo compressor outlet with the intercooler off. But it is probably worn with 107K miles, which is why I wanted to replace it before it goes horribly bad. I have the STi uppipe and VF52 waiting to get install. Just trying to tighten up the rest of the car before installing and loading a tune. Link to comment Share on other sites More sharing options...
relative4 Posted February 18, 2019 Share Posted February 18, 2019 To compensate for the lean condition presumably caused by the vacuum leaks (low fuel pressure is a possible but unlikely cause), the ECU is adding fuel to keep your A/F ratio safe. Have you smoke tested? Link to comment Share on other sites More sharing options...
700watts Posted February 18, 2019 Share Posted February 18, 2019 Sounds like a vacuum leak Link to comment Share on other sites More sharing options...
mondtster Posted February 18, 2019 Share Posted February 18, 2019 Sounds to me like you haven’t adjusted the delay before going to open loop, which you should. As far as making a determination on rich/lean goes, how long are you waiting after flashing the ECU or resetting it? I wouldn’t make any decisions until you have a few key cycles and 75-100 miles of mixed driving on it. Link to comment Share on other sites More sharing options...
Scoobiidoo Posted February 18, 2019 Author Share Posted February 18, 2019 @relative4 Haven't had it smoke tested yet. Don't know where to go to have it done in this middle of nowhere desert town. @700watts Besides the turbo inlet tube/hose, any other places I should look? Sounds to me like you haven’t adjusted the delay before going to open loop, which you should. As far as making a determination on rich/lean goes, how long are you waiting after flashing the ECU or resetting it? I wouldn’t make any decisions until you have a few key cycles and 75-100 miles of mixed driving on it. The log was after 150 miles of driving after ECU reset. The tune is stock map, I haven't change anything on it. Never really floored the throttle either when I said WOT, but it was enough to see immediate enrichment and hitting 9-10 psi boost with no leaning out. Link to comment Share on other sites More sharing options...
relative4 Posted February 18, 2019 Share Posted February 18, 2019 Smoke testers were $65 on eBay last I checked. Link to comment Share on other sites More sharing options...
mondtster Posted February 18, 2019 Share Posted February 18, 2019 Smoke testers were $65 on eBay last I checked. You can make one for a whole less than that too. Link to comment Share on other sites More sharing options...
Scoobiidoo Posted February 19, 2019 Author Share Posted February 19, 2019 Thanks guys. I am going to look into the smoke test. I was under the impression that it is a shop only type of testing equipment. Link to comment Share on other sites More sharing options...
Scoobiidoo Posted February 19, 2019 Author Share Posted February 19, 2019 Ordered a smoke tester for $55 shipped. It will be here next week. In the meantime, do I need to make a 3" PVC cap to pressure test it? Or can I just run the smoker without pressurizing it? Thanks. Link to comment Share on other sites More sharing options...
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