Found - LT Fuel Trim Control !!!
May 27, 2009, 01:57 AM
#46
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I have an idea that the RPM related map will only function when the MAF is in fault condition. I might check it out in the next few days. Been too busy to do any testing lately.
Last edited by Mattjin; May 27, 2009 at 02:08 AM.
May 28, 2009, 03:55 AM
#47
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Today I verified MUT50. You are right Acamus, MUT 50 shows the current Long Term Trim that the ECU is using. Interestingly there is no interpolation, it just plain switches from one trim to the next.
May 28, 2009, 08:43 AM
#48
Good for anyone trying to calibrate their MAF tables... it provides a much simpler way to log and calculate offsets if you are tuning in closed loop. This was very helpful when I calibrated my DSM.
Here is my Evoscan formula:
Code:
<DataListItem DataLog="Y" Color="" Display="Fuel Trim Current (LTFTC)" LogReference="FuelTrim_Current" RequestID="50" Eval="25*(x-128)/128" Unit="%" MetricEval="(0.1961*x)-25" MetricUnit="" ResponseBytes="1" GaugeMin="-15" GaugeMax="15" ChartMin="-15" ChartMax="15" ScalingFactor="1" Notes="Long Term Fuel Trim - Low, now represented in terms of a percentage. make sure you are within the 5% band, because outside of 5% you should rescale your injectors.

Old Formula: 0.78125*x" Priority="50" Visible="False" />
Last edited by fostytou; May 28, 2009 at 08:47 AM.
May 31, 2009, 04:54 PM
#51
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Hey all, I'm new to this kind of thing, and have been trying to log my Mid fuel trims, but have not been successful. (I have a 3rd gen eclipse RS turbo using a Evo 8 ECU, and have rescaled the MAS for HZ as well as added the LT Trims mentioned on the 1st page of this thread)
If I am not mistaken (someone please correct me if I'm wrong), being able to change when the ecu switches from low trims to mid trims would make doing changes to the injector voltage latencies a lot easier. (instead of driving around town, you could just let her idle and it would be okay because it is supposed to change the mid trims, but normally just idling would affect the LOW trims).
Looking at the table, from Low->Mid, lets say the value is 56.25 HZ. Would this mean that it would switch to the Mid Trim when the HZ value is 56.25 or above?
So in order for you to log the Mid Trims, would you lower it to whatever your HZ value is at IDLE? In my case, it is around 30HZ.
The thing is, I tried to do this, I let her idle, in closed loop, for 10 minutes or so (more than enough time for it to cycle) and the value hasn't changed.
Is there something I'm doing wrong or am I missing something?
Thanks in advance.
If I am not mistaken (someone please correct me if I'm wrong), being able to change when the ecu switches from low trims to mid trims would make doing changes to the injector voltage latencies a lot easier. (instead of driving around town, you could just let her idle and it would be okay because it is supposed to change the mid trims, but normally just idling would affect the LOW trims).
Looking at the table, from Low->Mid, lets say the value is 56.25 HZ. Would this mean that it would switch to the Mid Trim when the HZ value is 56.25 or above?
So in order for you to log the Mid Trims, would you lower it to whatever your HZ value is at IDLE? In my case, it is around 30HZ.
The thing is, I tried to do this, I let her idle, in closed loop, for 10 minutes or so (more than enough time for it to cycle) and the value hasn't changed.
Is there something I'm doing wrong or am I missing something?
Thanks in advance.
Jun 3, 2009, 06:19 AM
#52
I found the same, as mentioned earlier, for 96530006. I'm assuming the hz values indicate the switch over point between trims? I'm dealing with a car now that doesn't want to idle (272 Kelfords, BC valvetrain, +1mm valves, street head port, BBK Full, 3" hard pipe with Perrin filter, JMF exhaust/intake manis). Hz are staying in the high 50s to low 60s, and the LTFT low doesn't seem to be adjusting. My thought was the Hz was too high but, after putting this into the ROM it looks like the switch over point from LTFT low to mid is 72.50 so this doesn't seem to be the problem??
I'm going to try and scale the MAF to see if I can get the Hz down into the 40 range to see if that helps. Odd thing is that it idles just fine during warm-up but, once up to operating temp it just stales.
I'm going to try and scale the MAF to see if I can get the Hz down into the 40 range to see if that helps. Odd thing is that it idles just fine during warm-up but, once up to operating temp it just stales.
Jun 3, 2009, 09:35 AM
#53
I found the same, as mentioned earlier, for 96530006. I'm assuming the hz values indicate the switch over point between trims? I'm dealing with a car now that doesn't want to idle (272 Kelfords, BC valvetrain, +1mm valves, street head port, BBK Full, 3" hard pipe with Perrin filter, JMF exhaust/intake manis). Hz are staying in the high 50s to low 60s, and the LTFT low doesn't seem to be adjusting. My thought was the Hz was too high but, after putting this into the ROM it looks like the switch over point from LTFT low to mid is 72.50 so this doesn't seem to be the problem??
I'm going to try and scale the MAF to see if I can get the Hz down into the 40 range to see if that helps. Odd thing is that it idles just fine during warm-up but, once up to operating temp it just stales.
I'm going to try and scale the MAF to see if I can get the Hz down into the 40 range to see if that helps. Odd thing is that it idles just fine during warm-up but, once up to operating temp it just stales.
Jun 3, 2009, 10:36 PM
#54
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Hey all, I'm new to this kind of thing, and have been trying to log my Mid fuel trims, but have not been successful. (I have a 3rd gen eclipse RS turbo using a Evo 8 ECU, and have rescaled the MAS for HZ as well as added the LT Trims mentioned on the 1st page of this thread)
If I am not mistaken (someone please correct me if I'm wrong), being able to change when the ecu switches from low trims to mid trims would make doing changes to the injector voltage latencies a lot easier. (instead of driving around town, you could just let her idle and it would be okay because it is supposed to change the mid trims, but normally just idling would affect the LOW trims).
Looking at the table, from Low->Mid, lets say the value is 56.25 HZ. Would this mean that it would switch to the Mid Trim when the HZ value is 56.25 or above?
So in order for you to log the Mid Trims, would you lower it to whatever your HZ value is at IDLE? In my case, it is around 30HZ.
The thing is, I tried to do this, I let her idle, in closed loop, for 10 minutes or so (more than enough time for it to cycle) and the value hasn't changed.
Is there something I'm doing wrong or am I missing something?
Thanks in advance.
If I am not mistaken (someone please correct me if I'm wrong), being able to change when the ecu switches from low trims to mid trims would make doing changes to the injector voltage latencies a lot easier. (instead of driving around town, you could just let her idle and it would be okay because it is supposed to change the mid trims, but normally just idling would affect the LOW trims).
Looking at the table, from Low->Mid, lets say the value is 56.25 HZ. Would this mean that it would switch to the Mid Trim when the HZ value is 56.25 or above?
So in order for you to log the Mid Trims, would you lower it to whatever your HZ value is at IDLE? In my case, it is around 30HZ.
The thing is, I tried to do this, I let her idle, in closed loop, for 10 minutes or so (more than enough time for it to cycle) and the value hasn't changed.
Is there something I'm doing wrong or am I missing something?
Thanks in advance.
Jun 5, 2009, 02:08 PM
#56
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88580013, the MAF Hz map is at 3021. Be sure to re-read the first page because I had to rename the scale formula to avoid conflicts with some roms that already had the exact same scale name already. You can simply add the same scale and map for 88590015.
I always thought it strange that alot of rom will never use the High trim, but you can start using it by just lowering the switch points right down. Copying another rom's settings would be easy.
My suggestion for anyone having trim issues is to set the first two setting so that they are at least 30Hz above what your normal idle Hz. eg. My car idles in the 30's but the default settings are 75, 62, 156, 143. I have zero problems with trims.
I always thought it strange that alot of rom will never use the High trim, but you can start using it by just lowering the switch points right down. Copying another rom's settings would be easy.
My suggestion for anyone having trim issues is to set the first two setting so that they are at least 30Hz above what your normal idle Hz. eg. My car idles in the 30's but the default settings are 75, 62, 156, 143. I have zero problems with trims.
Last edited by Mattjin; Jun 5, 2009 at 02:13 PM.
Jun 6, 2009, 04:01 AM
#57
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Thanks Matt, looks good!
Or, at least the numbers are similar to others posted, but I dont know why mitsi set the mid-hi transition so high???
Your settings of 156-143 seem more reasonable, or is that just an auto thing?
Or, at least the numbers are similar to others posted, but I dont know why mitsi set the mid-hi transition so high???
Your settings of 156-143 seem more reasonable, or is that just an auto thing?
Jun 8, 2009, 12:43 AM
#58
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No, it is really dependant on the rom. Some utilise the High trim, others do not, but there is nothing stopping you from dropping the numbers so that it does activate. Maybe mitsu decided that some vehicles were pretty well sorted and did not need the extra trim.
I double checked and the rpm adjustment is not related to fault conditions... mostly because the closed loop system disables when the MAF is in fault. I would have thought it would rely more on it due to being limp with another sensor, but it is not the case. The RPM adjustment remains an unknown.
On a side note, I am probably nearing the end of my development because I am shortly about to put my evo up for sale and move on. I need something a little more baby-friendly in the near future. So that means ... errkkkk.... getting an SUV.
I double checked and the rpm adjustment is not related to fault conditions... mostly because the closed loop system disables when the MAF is in fault. I would have thought it would rely more on it due to being limp with another sensor, but it is not the case. The RPM adjustment remains an unknown.
On a side note, I am probably nearing the end of my development because I am shortly about to put my evo up for sale and move on. I need something a little more baby-friendly in the near future. So that means ... errkkkk.... getting an SUV.
