theclerk95 Posted September 26, 2019 Share Posted September 26, 2019 Hello everyone, I was just looking for some help on figuring out issues I have been having with my car since I got it dyno tuned back in June. The car is an 01 legacy b4 twin turbo with a stock ecu tuned using project lambda tuning software. Issues started when I couldn't get to my 7000rpm redline, which turns out the shop had accidentally lowered my redline to 6500. Reset the limiter back to 7000rpm. This was after I was told by them that it couldn't be the tune and was told to change my coilpacks and plugs. Fast forward to August and the car has issues with hesitation and goes into almost a limp mode intermittently. I notice that when running"good" i get 18psi on secondary turbo in 1st and 2nd gear but in 3rd it spikes up to 22 and then tapers. Everytime this happens there is no CEL but a stored code 23 for the MAF sensor. Have tried replacing the MAF, replacing the o2 sensor, smoke tested for leaks and checked all solenoids and the MAP sensor and all is good. I decided to look at my tune, and I noticed that my MAF calibration has been changed when the car is hitting boost, and me not knowing anything about tuning thought that maf calibration was only changed when running a bigger/aftermarket intake. My car has a fuel pump, full decat exhaust, and has been switched to a fmic with a recirculating bov, but is still running a factory maf and maf housing, so should the calibration not still be the same instead of being altered? and could this possibly be the issue I have been having with the car throwing the maf code and the occasional issue with hesitation? Thanks for any help in advance, as I really don't know much with tuning, and am just trying everything to get to the bottom of this issue. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 26, 2019 Share Posted September 26, 2019 It is my understanding that if the intake is still stock, the MAF calibration (particularly closed loop) does not need to be altered. Are you able to log and view parameters live when you drive? Can you post your long term fuel trims? Link to comment Share on other sites More sharing options...
theclerk95 Posted September 26, 2019 Author Share Posted September 26, 2019 It is my understanding that if the intake is still stock, the MAF calibration (particularly closed loop) does not need to be altered. Are you able to log and view parameters live when you drive? Can you post your long term fuel trims? Hi yes I am able to, will do a quick log and post that up when it's done. And yeah I always thought maf calibration wasn't necessary for a stock intake. Looked back at old maps my old tuner did for me and he had never once adjusted the maf calibration Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 26, 2019 Share Posted September 26, 2019 Yeah. So report your four long term fuel trims for the various MAF ranges in g/s. You want them to be close to 0%. That would mean that the air/fuel mixture is right. This would also imply that you are free of vacuum/boost leaks, and that your MAF and o2 sensors are working OK. Link to comment Share on other sites More sharing options...
theclerk95 Posted September 26, 2019 Author Share Posted September 26, 2019 Yeah. So report your four long term fuel trims for the various MAF ranges in g/s. You want them to be close to 0%. That would mean that the air/fuel mixture is right. This would also imply that you are free of vacuum/boost leaks, and that your MAF and o2 sensors are working OK. this would be one log that I had back from last month not sure if that shows anything of any usetuner_log_19-08-29_0719.csv Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 26, 2019 Share Posted September 26, 2019 Just looked at it. I looked at the MAF reading, Fuel trim -long term and short term, and rpm. This log is just an idle log. We also want to see the long term fuel trims for like cruising and WOT conditions. In any case, this log is showing that you are running pretty lean. As a result, the ECU hard learned to add about 8-12% of fuel, which is somewhat high. You want the values to stay close to 0%. Positive values may indicate a vacuum leak. So carefully check for any. Link to comment Share on other sites More sharing options...
theclerk95 Posted September 26, 2019 Author Share Posted September 26, 2019 Just looked at it. I looked at the MAF reading, Fuel trim -long term and short term, and rpm. This log is just an idle log. We also want to see the long term fuel trims for like cruising and WOT conditions. In any case, this log is showing that you are running pretty lean. As a result, the ECU hard learned to add about 8-12% of fuel, which is somewhat high. You want the values to stay close to 0%. Positive values may indicate a vacuum leak. So carefully check for any. oh okay figured that was just an idle one where the file size was so small. Will get some logs tomorrow and post them up. Thanks for checking that out. This was also before we did a smoke test and found my catch can setup was leaking air. Replaced it and smoke tested again and found no leaks, but issues still persist. Will try a log with the tune the way it is now, and then another log with the maf calibration set back to stock to see if theres any difference and post them Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 26, 2019 Share Posted September 26, 2019 well, you said this was an old log. The long term fuel trims can change very quickly actually and many times in a day. So your idle LTFT may be completely different now. So do an idle log, a cruise log, and maybe a wot log. Although I personally avoid wot logs when I know the car is not happy. Link to comment Share on other sites More sharing options...
theclerk95 Posted September 28, 2019 Author Share Posted September 28, 2019 well, you said this was an old log. The long term fuel trims can change very quickly actually and many times in a day. So your idle LTFT may be completely different now. So do an idle log, a cruise log, and maybe a wot log. Although I personally avoid wot logs when I know the car is not happy. well went ahead and did a log of idle, cruising and wot. Did one for the dyno tune and one for the same tune with the maf calibration put back to stock. Didn't help my issue unfortunately. Did notice the maf voltage drops below 0.3V for a split second in spots, and am thinking maybe there is a wiring issue on the maf harness. I had asked the shop to check out the wiring when I took it in to get diagnosed, I asked them to confirm after seeing this log and turns out they didn't because the voltage was fine at idle. I'm thinking there must be a break somewhere thats showing up when in motion or boost possibly. Here is the logs though with the dyno tunetuner_log_19-09-27_0710.csvtuner_log_19-09-27_0718.csvtuner_log_19-09-27_0723.csvtuner_log_19-09-27_0726.csv Link to comment Share on other sites More sharing options...
theclerk95 Posted September 28, 2019 Author Share Posted September 28, 2019 and then here are the logs from the same tune with maf calibration changed to stocktuner_log_19-09-27_1204.csvtuner_log_19-09-27_1212.csvtuner_log_19-09-27_1216.csvtuner_log_19-09-27_1220.csv Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 28, 2019 Share Posted September 28, 2019 I'll have a look later. But in the meantime, you should perform a simple test: idle the engine, take your laptop with you if you can and watch the fuel correct trim as you bend and move the maf wiring harness from various location (i.e. close to the maf, mid way, etc...). Perhaps the connection at the MAF is poor or the wires are indeed bad. happened to me before. If that's the case, you will notice the ecu try doing some corrections right away. You will also hear the idle change. Link to comment Share on other sites More sharing options...
theclerk95 Posted September 28, 2019 Author Share Posted September 28, 2019 yeah I tried tugging/wiggling them and the connector and didn't really notice any changes. I am gonna try and spray the connector with some maf cleaner, and move the harness into another position as it is between my intercooler pipe and my solenoid box so maybe its getting pinched somehow Link to comment Share on other sites More sharing options...
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