So I'm still troubleshooting this issue but I want to bounce it off of you guys while I'm at it. Car: 2013 sti Mods: Catless turbo back, ID1000, cobb fpr kit, fuel pump, everything else is stock. Currently on e74. Stock plugs, probably original. Grimmspeed ebcs. And iag aos street. Problem: Air fuel learn on the ap is 10% during idle. It's about that high when the engine is in vacuum while cruising. It is oscillating a lot at 0 boost. I noticed wot is a little richer than expected, but I was playing with my fuel map in the last few revisions, so I don't know if it's related to a leak or my changes. This morning, I shot engine starter around the intake track to see if I could hear the idle come up. Didn't hear anything. In retrospect, I should have data logged af correction, which I'll do tonight. I don't have a intake pressure tested but Im sure I can get one. Just thought I'd start with what I have. More info: Wasn't always this high but I don't have an exact day when it got this bad. I put a K and N typhoon intake on but didn't like the noise so I went back to stock and I don't remember seeing weird af learn when I put it back in. I also put the fpr reference on the bpv vacuum line and a boost gauge on the old fpr reference location. The gauge didn't feel like it holds onto that nipple well, but I don't see oscillation on the gauge during idle. I think I first noticed it when I recently got a full tank of e80. My first assumption was I tuned the injector scale wrong but I went back and did my math and everything looked right. I filled a second tank to e74 and the af learn stayed around 10%. Reset ecu and flashed a few miner changes in accesstuner with the same results. Fuel pressure sensor error (target 43.7?) wasn't that far from 0 so I don't think its related to fuel delivery. I checked the intake fittings and they seem tight. Tonight I'll refit them. For the tuners: In a few revisions of my tune, I wanted to tackle the fpr and I though I did this (I thought) successfully by multiplying the maf load compensation table by 20% and flattened/zeroed out the spaces around the higher values. Running that map this morning didn't change idle and I didn't drive long enough to tell its impact on cruise. There were other changes but I'd have to look. I made some other map changes and wouldn't mind talking about what I did if you message me. Data logs show a steady afr but the correction tends to bounce around more than I'd like. I'd really like to learn more from a tuner if anyone's willing to teach
Annnd.. Solved the rich at wot issue. Nommnom... Still don't know why af learns are all over the place... Unfortunately today got real worse, real fast when this happened. (totally unrelated to the intake issue).. Update: Went to a shop that a friend works at and we tossed a smoke tester on the intake. I found smoke coming from the front of the TGV valve on the driver side... My guess is that there may be issues with those valves, but I dont know why it running ok until now. If this is it, it looks like ill have to do a TGV delete.
