Trim issue
EvoM Guru
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From: Tri-Cities, WA // Portland, OR
Something isn't making sense here. If the curise AFRs are in the 13s and low 14s, then the STFT should be pretty negative. Cruise and idle should be stoich.
I think there is a way to log whether the car is in open loop or closed loop. That would be some good info to have.
Although I'm not sure if STFT bounces around or not in open loop.
I think there is a way to log whether the car is in open loop or closed loop. That would be some good info to have.
Although I'm not sure if STFT bounces around or not in open loop.
My LC-1 averages at about 14.5:1 during closed loop cruise. Lots of other people have seen similar. By "13s and low 14s", do you mean that the LC-1 bounces between, say 13.5:1 and 14.3:1? If yes, then that's a bit too rich even for an LC-1.
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From: Sellersville, PA
If the car is in open loop, the STFT goes to zero, so its definitely in closed loop. Its wierd that the LTFTs are not working. I've been running my rear O2 sim for over a year, and my LTFTs have always worked as expected. tephra is using my rear O2 sim in his ROMs, so it wouldn't make sense that the rear O2 sim is the issue. I'm leaning towards some wierd periphery values. Can you post the values?
My LC-1 averages at about 14.5:1 during closed loop cruise. Lots of other people have seen similar. By "13s and low 14s", do you mean that the LC-1 bounces between, say 13.5:1 and 14.3:1? If yes, then that's a bit too rich even for an LC-1.
My LC-1 averages at about 14.5:1 during closed loop cruise. Lots of other people have seen similar. By "13s and low 14s", do you mean that the LC-1 bounces between, say 13.5:1 and 14.3:1? If yes, then that's a bit too rich even for an LC-1.
I attached the Periphery bits in the ROM below. One thing I have changed but, haven't tried yet on the car is that I re-enabled FAA bit 01 as I noticed it dealt with the rear O2 sensor.
I'm going to go for another cruise tomorrow night for an extended period to double check the LC1 readings.
The car idles rock solid with STFT between -1 to +2 with the LC1 showing low to mid 14s at idle but, no LTFT lows are at all.
Should I try adding the below from your other post in the other trim thread:
The "0.1008" value is because the exact decimal value is not in the EvoScan fuel trim formula. The following EvoScan entries will give you zero values for the fuel trims when they really are zero:
<DataListItem DataLog="N" Color="" Display="LT Fuel Trim Low" LogReference="LTFT_Low" RequestID="0C" Eval="0.1953125*x-25" Unit="%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-13" GaugeMax="13" ChartMin="-13" ChartMax="13" ScalingFactor="1" Notes="" Priority="1" Visible="false" />
<DataListItem DataLog="N" Color="" Display="LT Fuel Trim Mid" LogReference="LTFT_Mid" RequestID="0D" Eval="0.1953125*x-25" Unit="%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-13" GaugeMax="13" ChartMin="-13" ChartMax="13" ScalingFactor="1" Notes="" Priority="1" Visible="false" />
<DataListItem DataLog="N" Color="" Display="ST Fuel Trim" LogReference="STFT" RequestID="0F" Eval="0.1953125*x-25" Unit="%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-25" GaugeMax="25" ChartMin="0" ChartMax="200" ScalingFactor="1" Notes="" Priority="1" Visible="False" />
<DataListItem DataLog="N" Color="" Display="LT Fuel Trim Low" LogReference="LTFT_Low" RequestID="0C" Eval="0.1953125*x-25" Unit="%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-13" GaugeMax="13" ChartMin="-13" ChartMax="13" ScalingFactor="1" Notes="" Priority="1" Visible="false" />
<DataListItem DataLog="N" Color="" Display="LT Fuel Trim Mid" LogReference="LTFT_Mid" RequestID="0D" Eval="0.1953125*x-25" Unit="%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-13" GaugeMax="13" ChartMin="-13" ChartMax="13" ScalingFactor="1" Notes="" Priority="1" Visible="false" />
<DataListItem DataLog="N" Color="" Display="ST Fuel Trim" LogReference="STFT" RequestID="0F" Eval="0.1953125*x-25" Unit="%" MetricEval="" MetricUnit="" ResponseBytes="1" GaugeMin="-25" GaugeMax="25" ChartMin="0" ChartMax="200" ScalingFactor="1" Notes="" Priority="1" Visible="False" />
EvoM Guru
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From: Tri-Cities, WA // Portland, OR
I've had no problems in the past either with your rear O2 sim patch and fuel trims. I did though try disabling it this time but, it made no difference.
I attached the Periphery bits in the ROM below. One thing I have changed but, haven't tried yet on the car is that I re-enabled FAA bit 01 as I noticed it dealt with the rear O2 sensor.
I'm going to go for another cruise tomorrow night for an extended period to double check the LC1 readings.
The car idles rock solid with STFT between -1 to +2 with the LC1 showing low to mid 14s at idle but, no LTFT lows are at all.
Should I try adding the below from your other post in the other trim thread:
I attached the Periphery bits in the ROM below. One thing I have changed but, haven't tried yet on the car is that I re-enabled FAA bit 01 as I noticed it dealt with the rear O2 sensor.
I'm going to go for another cruise tomorrow night for an extended period to double check the LC1 readings.
The car idles rock solid with STFT between -1 to +2 with the LC1 showing low to mid 14s at idle but, no LTFT lows are at all.
Should I try adding the below from your other post in the other trim thread:
Definitely set FAA bit1 back to 1. Why would anyone disable that when its not clear what it does.
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Evolved Member
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From: Sellersville, PA
Mfred.....those EvoScan trim values work like a champ. You are the MAN ! !
evo8dad.....my FAA bit 1 is set to 1 and has never been changed. You would be best to change it back to a 1 as Mfred said.
evo8dad.....my FAA bit 1 is set to 1 and has never been changed. You would be best to change it back to a 1 as Mfred said.
Thread Starter
Evolved Member
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Joined: Apr 2003
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From: Sellersville, PA
The odd thing is that I never messed with that bit and didn't notice it was disabled until I went searching to make sure everything was cool in the peripheries.
Thread Starter
Evolved Member
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From: Sellersville, PA
Mr Fred - you saved the day with your new trim definitions. After all my head scratching the trims where in fact dead on. With your new definitions for the trims I was able to see that the LTFT low was actually reading, just at +.585 (12r99gst you were right 
). Thank you very much for those definitions.
Now I can finally move on to scaling these 750s.
The only odd thing is that the LC1 is reading showing afrs between 14.1 - 14.6. I'm not that concerned about it at this point as the car idles like a champ and the trims are spot on. I haven't gone for a cruise yet to check cruise afrs though.
). Thank you very much for those definitions. Now I can finally move on to scaling these 750s.
The only odd thing is that the LC1 is reading showing afrs between 14.1 - 14.6. I'm not that concerned about it at this point as the car idles like a champ and the trims are spot on. I haven't gone for a cruise yet to check cruise afrs though.
These settings should get you in the ball park with 750s....
Scaling = 696
Latencies =
4.6875 = 3.213
7.03125 = 2.040
9.375 = 1.296
11.7188 = 0.912
14.0625 = 0.792
16.4062 = 0.600
18.6768 = 0.336
For my car they are spot on with all trims hovering + / - 3
Scaling = 696
Latencies =
4.6875 = 3.213
7.03125 = 2.040
9.375 = 1.296
11.7188 = 0.912
14.0625 = 0.792
16.4062 = 0.600
18.6768 = 0.336
For my car they are spot on with all trims hovering + / - 3
I went back to my 696 scaling and latencies as I found they are more accurate in reference to my Fuel table when I do a pull.
Also, I swapped back in the stock rubber intake pipe and my MAF hz dropped from 50 to 30 and instantly my LTFT Low started adjusting.
Also, I swapped back in the stock rubber intake pipe and my MAF hz dropped from 50 to 30 and instantly my LTFT Low started adjusting.
Since John (jcsbanks) went through the entire airflow routine, maybe he can answer how to adjust the Maf Hz reading, if it is reading too high. I don't know if it's possible, but he would know if anyone would at this point.
Funny the owner couldn't pass emissions due to another change that was made on top of that one that interfered with how the inspection equipment connected to the ecu.....
