need help with a/f at idel
dont see any numbers.
would you like for me to send you my tune so you can look at it.
edit i do see a 513 in there.
under
converts to i have
1
504.155
513
1008.31
Last edited by filter; Feb 14, 2008 at 05:23 PM.
Let's talk about your log. OK, your short term fuel trim goes anywhere from +3 to +15%. Your LTFTs aren't being affected yet. After a good 5-10 minute idle, these values should have begun to push into your LTFT Lo. So, I don't know if your car is set to run open loop or if you just haven't met the conditions for the LTFT to change yet.
If you want to send me your tune, that's fine. I will take a look...it may be easier than asking you a million questions.
Anyway, assuming that you are in closed loop and your LTFTs just haven't updated yet, it looks like the LTFT Lo will eventually be around +10%. That is still in the adjustable range, but near it's max. I'm wondering if you have two issues here...I'm wondering if there is an exhaust leak before your wideband. Because from the log above, the ECU was within it's adjustment range, so the idle should have been at stoich (14.7:1) on the wideband.
I can tell you what to increase your MAF scaling to to get rid of the positive correction in the STFT, but if you have a leak before your WB, then you will still show a lean reading.
I will PM you my email address to send the tune. And I will tell you what to adjust your MAF scaling to.
Eric
No, I meant what is your injector scaling listed at when you click that map in ECUFLash. It should just be one number. The right clicking I asked about was for the MAF scaling. Don't worry about that now.
Let's talk about your log. OK, your short term fuel trim goes anywhere from +3 to +15%. Your LTFTs aren't being affected yet. After a good 5-10 minute idle, these values should have begun to push into your LTFT Lo. So, I don't know if your car is set to run open loop or if you just haven't met the conditions for the LTFT to change yet.
If you want to send me your tune, that's fine. I will take a look...it may be easier than asking you a million questions.
Anyway, assuming that you are in closed loop and your LTFTs just haven't updated yet, it looks like the LTFT Lo will eventually be around +10%. That is still in the adjustable range, but near it's max. I'm wondering if you have two issues here...I'm wondering if there is an exhaust leak before your wideband. Because from the log above, the ECU was within it's adjustment range, so the idle should have been at stoich (14.7:1) on the wideband.
I can tell you what to increase your MAF scaling to to get rid of the positive correction in the STFT, but if you have a leak before your WB, then you will still show a lean reading.
I will PM you my email address to send the tune. And I will tell you what to adjust your MAF scaling to.
Eric
Let's talk about your log. OK, your short term fuel trim goes anywhere from +3 to +15%. Your LTFTs aren't being affected yet. After a good 5-10 minute idle, these values should have begun to push into your LTFT Lo. So, I don't know if your car is set to run open loop or if you just haven't met the conditions for the LTFT to change yet.
If you want to send me your tune, that's fine. I will take a look...it may be easier than asking you a million questions.
Anyway, assuming that you are in closed loop and your LTFTs just haven't updated yet, it looks like the LTFT Lo will eventually be around +10%. That is still in the adjustable range, but near it's max. I'm wondering if you have two issues here...I'm wondering if there is an exhaust leak before your wideband. Because from the log above, the ECU was within it's adjustment range, so the idle should have been at stoich (14.7:1) on the wideband.
I can tell you what to increase your MAF scaling to to get rid of the positive correction in the STFT, but if you have a leak before your WB, then you will still show a lean reading.
I will PM you my email address to send the tune. And I will tell you what to adjust your MAF scaling to.
Eric
OK, for the record, I took a look at his tune and everything seems stock in terms of injector scaling, open loop loads, etc.
So, looking at his log more (the longer idle), his front O2 sensor is functioning normally. It is bouncing around .5V, meaning that the car is actually maintaining a stoich burn (14.7:1) at idle. His STFT seems to be averaging about +10% though, but that is still within the range of ECU control.
So, my conclusion here is that there is an exhaust leak before the zzzWB sensor or an issue with the WB sensor. There can also be an issue with the front O2 sensor, but it looks OK from the logs.
So, what I suggest is to make sure that the downpipe is sealing correctly to the O2 housing. An exhaust leak here will cause idle AFRs to read lean on a wideband, even though the car is actually running stoich. This leak won't cause the WOT AFR to read lean though because at WOT the airflow substantially more than at idle, so it makes the leak negligible in terms of the wideband reading. (I have seen this in the past on another car that I had).
Anyway, to fix the +10% trims I gave him new values to put into the first two cells in the MAF scaling table, to increase the fueling by 10% at idle. This should bring the trims to around 0, but if there is an exhaust leak or WB issue, then the idle will still read lean.
Eric
So, looking at his log more (the longer idle), his front O2 sensor is functioning normally. It is bouncing around .5V, meaning that the car is actually maintaining a stoich burn (14.7:1) at idle. His STFT seems to be averaging about +10% though, but that is still within the range of ECU control.
So, my conclusion here is that there is an exhaust leak before the zzzWB sensor or an issue with the WB sensor. There can also be an issue with the front O2 sensor, but it looks OK from the logs.
So, what I suggest is to make sure that the downpipe is sealing correctly to the O2 housing. An exhaust leak here will cause idle AFRs to read lean on a wideband, even though the car is actually running stoich. This leak won't cause the WOT AFR to read lean though because at WOT the airflow substantially more than at idle, so it makes the leak negligible in terms of the wideband reading. (I have seen this in the past on another car that I had).
Anyway, to fix the +10% trims I gave him new values to put into the first two cells in the MAF scaling table, to increase the fueling by 10% at idle. This should bring the trims to around 0, but if there is an exhaust leak or WB issue, then the idle will still read lean.
Eric
OK, for the record, I took a look at his tune and everything seems stock in terms of injector scaling, open loop loads, etc.
So, looking at his log more (the longer idle), his front O2 sensor is functioning normally. It is bouncing around .5V, meaning that the car is actually maintaining a stoich burn (14.7:1) at idle. His STFT seems to be averaging about +10% though, but that is still within the range of ECU control.
So, my conclusion here is that there is an exhaust leak before the zzzWB sensor or an issue with the WB sensor. There can also be an issue with the front O2 sensor, but it looks OK from the logs.
So, what I suggest is to make sure that the downpipe is sealing correctly to the O2 housing. An exhaust leak here will cause idle AFRs to read lean on a wideband, even though the car is actually running stoich. This leak won't cause the WOT AFR to read lean though because at WOT the airflow substantially more than at idle, so it makes the leak negligible in terms of the wideband reading. (I have seen this in the past on another car that I had).
Anyway, to fix the +10% trims I gave him new values to put into the first two cells in the MAF scaling table, to increase the fueling by 10% at idle. This should bring the trims to around 0, but if there is an exhaust leak or WB issue, then the idle will still read lean.
Eric
So, looking at his log more (the longer idle), his front O2 sensor is functioning normally. It is bouncing around .5V, meaning that the car is actually maintaining a stoich burn (14.7:1) at idle. His STFT seems to be averaging about +10% though, but that is still within the range of ECU control.
So, my conclusion here is that there is an exhaust leak before the zzzWB sensor or an issue with the WB sensor. There can also be an issue with the front O2 sensor, but it looks OK from the logs.
So, what I suggest is to make sure that the downpipe is sealing correctly to the O2 housing. An exhaust leak here will cause idle AFRs to read lean on a wideband, even though the car is actually running stoich. This leak won't cause the WOT AFR to read lean though because at WOT the airflow substantially more than at idle, so it makes the leak negligible in terms of the wideband reading. (I have seen this in the past on another car that I had).
Anyway, to fix the +10% trims I gave him new values to put into the first two cells in the MAF scaling table, to increase the fueling by 10% at idle. This should bring the trims to around 0, but if there is an exhaust leak or WB issue, then the idle will still read lean.
Eric
i will be checking this out firday or saturday when i can get it on the lift.
Same with me. My idle was about 17:1 and WOT was unaffected. I can't recall if cruise was affected either. It would depend on how big the leak was and what cruising conditions were. But, in general if you see lean idle AFRs and your trims are in check, then that points to an exhaust leak before the sensor.
Yeah, if it really is an exhaust leak, the WB wouldn't read any differently.
When you get a chance to check the downpipe this weekend, also make sure to get a nice long idle, like 10-15 minutes if you can. Then do a log. Your LTFTs should NOT be 0 at that time. The STFT should be pushed over into the LTFT.
When you get a chance to check the downpipe this weekend, also make sure to get a nice long idle, like 10-15 minutes if you can. Then do a log. Your LTFTs should NOT be 0 at that time. The STFT should be pushed over into the LTFT.
Last edited by l2r99gst; Feb 14, 2008 at 07:34 PM.