Volcom86 Posted February 11, 2021 Report Share Posted February 11, 2021 Hi guys, I have a question in regards to when I stump on the throttle to 100% at lower RPM cruise RPM the Air Fuel will go lean and the car will sometimes stutter then go back to normal. ( I have only been doing this to log and show the data on what its doing) Would this be due to a bad low load VE Table or close loop fueling or Accel Enrichment? If I progressively increase the % of TP it's a lot better Running 1,700cc ID Injectors Attached log and map Thank you https://www.dropbox.com/s/endueqn9by4ofnv/feb 11 v7.llg?dl=0 Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 11, 2021 Report Share Posted February 11, 2021 I would say some of it is due to accel enrichment, you can see below you only get about 10% enrichment and allowing for the slight delay in lambda response your leanest bump happens right around where the throttle is still moving. However, even after that lean bump the AFR still stays quite a bit leaner than target for the whole WOT bit so there is something else wrong in that area too. I would add about another 10% to the 2500 & 3000rpm cells of the accel clamp table and see if that helps. Volcom86 1 Quote Link to comment Share on other sites More sharing options...
Volcom86 Posted February 16, 2021 Author Report Share Posted February 16, 2021 On 2/11/2021 at 7:05 PM, Adamw said: I would say some of it is due to accel enrichment, you can see below you only get about 10% enrichment and allowing for the slight delay in lambda response your leanest bump happens right around where the throttle is still moving. However, even after that lean bump the AFR still stays quite a bit leaner than target for the whole WOT bit so there is something else wrong in that area too. I would add about another 10% to the 2500 & 3000rpm cells of the accel clamp table and see if that helps. Thanks @Adamw I have tried to play around with the Accel Clamp Table and I saw no difference. What I did try was switching from FP-Sensor to LOAD=MAP and I have notice an improvement Could this potentially be a faulty Fuel Pressure Sensor giving me this drama with the quick lean spike conditions ? Thank you Attached updated MAP File and LOG File https://www.dropbox.com/s/pc3tsvbkvdln2lu/Simon 05 STI Final PLEX SDM500 lower WG DC 2 MAP.llg?dl=0 Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 16, 2021 Report Share Posted February 16, 2021 I think that has just masked the issue a bit. Since your base fuel pressure setting was 300Kpa, but you actually have more like 345kpa, when you change to "MAP referenced mode" the ecu thinks your fuel pressure is lower and just increases pulse width all over. I dont really see any obvious signs that your fuel pressure regulator or fuel pressure sensor isnt working correctly. Differential pressure appears to be well controlled during transients. In the pic below the original log is the coloured lines, and we are looking at the same lean spot area as you pointed out originally above. The overlayed pink lines are from the new log, the closest operating conditions I can find (MAP is just a tiny bit higher). You will notice in the pink traces the ecu thinks the differential pressure has dropped to 300kpa, so it has increased the injector PW from the original 2.89ms up to 3.62ms, but if we look at the pink lambda trace there is still a lean spike in exactly the same area - just not as bad since you have like an extra 30% PW going in. You will notice the pink lambda trace is richer pretty much everywhere. Volcom86 1 Quote Link to comment Share on other sites More sharing options...
Volcom86 Posted February 16, 2021 Author Report Share Posted February 16, 2021 Thank you @Adamw I appreciate your feedback. I do not know what it might be. I have replaced the Lambda Sensor not that long ago as my old sensor gave up. It fixed allot of other issues that I was experiencing however the new sensor never fixed lean condition. Quote Link to comment Share on other sites More sharing options...
Volcom86 Posted February 22, 2021 Author Report Share Posted February 22, 2021 @Adamw I might have an answer to my problem. When we changed the lambda sensor for some reason it was in my map showing as a Zetronix Z3... Even though I have a AEM X-Series gauge... This is how it was tuned under Zetronix Z3. I have changed to a NEW AEM Lambda Sensor few months ago but never changed the settings in the file to change from Zetronix Z3 to a AEM X-Series as it just worked I have had a play with the settings today and noticed when switching from Zetronix Z3 to AEM X-Series settings the AFR becomes more richer about 2 points richer. Would this mean I would need to have the car retuned if I wanted to switch the settings from Zetronix Z3 to AEM X-Series for example https://www.dropbox.com/s/yh4kyj4qexmoelm/original map AEM 22.llg?dl=0 LOG FILE AEM SETTINGS I am not sure if these two would have an effect on my Lean spike AFR Thank you. I hope the above all makes sense Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 23, 2021 Report Share Posted February 23, 2021 Yes, if the fuel table has been tuned using a lambda with a significantly wrong calibration, the the fuel table will need to be re-tuned. DenisAlmos and Volcom86 1 1 Quote Link to comment Share on other sites More sharing options...
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