Installed LM-1, says it's too lean
04-03-2007, 08:40 PM
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Installed LM-1, says it's too lean Installed the O2 sensor 180* from the NBO2 in the header collector at 9 o'clock on the passenger side.
Followed instructions exactly.
Went for a drive down the highway, it reads an average of 14.7 most of the time, although it's not steady at all. At WOT it doesn't always change but it did log a few times at 13.4.
sometimes while coasting down it would go off the chart at 20 other times doing the same thing it would hit 12.8 or so for a second.
I don't know what to think of this, any idea whats going on?
There are no exhaust leaks.
The car is an '02 ss with a six speed conversion, 3.73 rear, HPTuners used to convert the VCM, slp lid, K&N filter, pacesetter lt headers, no a.i.r. , ory. Nothing special.
Tuning is stock except the PE enable is lowered from 5500 to 5000 rpm, and the EQ ratio vs RPM was changed to 1.152 all the way accross.
Any suggestions?
Followed instructions exactly.
Went for a drive down the highway, it reads an average of 14.7 most of the time, although it's not steady at all. At WOT it doesn't always change but it did log a few times at 13.4.
sometimes while coasting down it would go off the chart at 20 other times doing the same thing it would hit 12.8 or so for a second.
I don't know what to think of this, any idea whats going on?
There are no exhaust leaks.
The car is an '02 ss with a six speed conversion, 3.73 rear, HPTuners used to convert the VCM, slp lid, K&N filter, pacesetter lt headers, no a.i.r. , ory. Nothing special.
Tuning is stock except the PE enable is lowered from 5500 to 5000 rpm, and the EQ ratio vs RPM was changed to 1.152 all the way accross.
Any suggestions?
04-04-2007, 04:10 PM
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Any idea why my afr stays at 14.7 +/- .8 all the time? Even under wot PE?
Wait, why is this forum here?
Originally Posted by horist
most people who buy full tuning software do so because they want to learn how to tune themselves... which is why this forum is here, and other forums.
04-04-2007, 04:57 PM
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So you have a modded car that's untuned and you want to know why it's running lean?
To answer your questions, you should check the stickies at the top of this forum - mainly the one labeled READ ME FIRST. There are several tuning 101 documents in there that can explain what you're asking.
To answer your questions, you should check the stickies at the top of this forum - mainly the one labeled READ ME FIRST. There are several tuning 101 documents in there that can explain what you're asking.
04-04-2007, 05:36 PM
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No sure what you're asking - why does it go lean on decel? The fuel cutoff and the TPS at or near 0 cuts fuel but you are still pulling air - I don't see a probelm with what you are seeing.
04-04-2007, 06:10 PM
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Originally Posted by DaddySS
No sure what you're asking - why does it go lean on decel? The fuel cutoff and the TPS at or near 0 cuts fuel but you are still pulling air - I don't see a probelm with what you are seeing.
Any idea why my afr stays at 14.7 +/- .8 all the time? Even under wot PE?
04-04-2007, 06:12 PM
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Originally Posted by SSpdDmon
So you have a modded car that's untuned and you want to know why it's running lean?
To answer your questions, you should check the stickies at the top of this forum - mainly the one labeled READ ME FIRST. There are several tuning 101 documents in there that can explain what you're asking.
To answer your questions, you should check the stickies at the top of this forum - mainly the one labeled READ ME FIRST. There are several tuning 101 documents in there that can explain what you're asking.
I don't know if it's tuning 101, seems more like a problem because the AFR never changes. I can't find anything about that.
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04-04-2007, 06:17 PM
#8
Mid-high 13s:1 on a modded untuned car; mmm mmmm mmmm like choclate and peanut butter 
The 20:1 at decel is DFCO cutting fuel as noted above. Your trims will swing fuel back and forth to try and maintain about 14.7:1. Hook up to your LM1 with the laptop and turn down the sampling speed; it's default I believe is it's fastest update and it catches fuel swing on the way up and down, so you get bouncing numbers at cruise in closed loop. If you cut the update back it averages much better.
The 20:1 at decel is DFCO cutting fuel as noted above. Your trims will swing fuel back and forth to try and maintain about 14.7:1. Hook up to your LM1 with the laptop and turn down the sampling speed; it's default I believe is it's fastest update and it catches fuel swing on the way up and down, so you get bouncing numbers at cruise in closed loop. If you cut the update back it averages much better.
04-04-2007, 06:23 PM
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Cool someone understands, thanks for your time, I really appreciate it.
Originally Posted by Frost
Mid-high 13s:1 on a modded untuned car; mmm mmmm mmmm like choclate and peanut butter The 20:1 at decel is DFCO cutting fuel as noted above. Your trims will swing fuel back and forth to try and maintain about 14.7:1. Hook up to your LM1 with the laptop and turn down the sampling speed; it's default I believe is it's fastest update and it catches fuel swing on the way up and down, so you get bouncing numbers at cruise in closed loop. If you cut the update back it averages much better.
The 20:1 at decel is DFCO cutting fuel as noted above. Your trims will swing fuel back and forth to try and maintain about 14.7:1. Hook up to your LM1 with the laptop and turn down the sampling speed; it's default I believe is it's fastest update and it catches fuel swing on the way up and down, so you get bouncing numbers at cruise in closed loop. If you cut the update back it averages much better.
04-04-2007, 07:54 PM
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Originally Posted by 8a8mfh
Installed the O2 sensor 180* from the NBO2 in the header collector at 9 o'clock on the passenger side.
Followed instructions exactly.
Went for a drive down the highway, it reads an average of 14.7 most of the time, although it's not steady at all. At WOT it doesn't always change but it did log a few times at 13.4.
sometimes while coasting down it would go off the chart at 20 other times doing the same thing it would hit 12.8 or so for a second.
I don't know what to think of this, any idea whats going on?
There are no exhaust leaks.
The car is an '02 ss with a six speed conversion, 3.73 rear, HPTuners used to convert the VCM, slp lid, K&N filter, pacesetter lt headers, no a.i.r. , ory. Nothing special.
Tuning is stock except the PE enable is lowered from 5500 to 5000 rpm, and the EQ ratio vs RPM was changed to 1.152 all the way accross.
Any suggestions?
Followed instructions exactly.
Went for a drive down the highway, it reads an average of 14.7 most of the time, although it's not steady at all. At WOT it doesn't always change but it did log a few times at 13.4.
sometimes while coasting down it would go off the chart at 20 other times doing the same thing it would hit 12.8 or so for a second.
I don't know what to think of this, any idea whats going on?
There are no exhaust leaks.
The car is an '02 ss with a six speed conversion, 3.73 rear, HPTuners used to convert the VCM, slp lid, K&N filter, pacesetter lt headers, no a.i.r. , ory. Nothing special.
Tuning is stock except the PE enable is lowered from 5500 to 5000 rpm, and the EQ ratio vs RPM was changed to 1.152 all the way accross.
Any suggestions?
The lean on decel is also normal and is decel fuel cut off, it cuts fuelk when you come off the gas pedal.
A 1.152 in the PE table is a commanded AFr of 12.7 yet your actual read AFR is 13.4, all that means is that your VE and MAF tables need to be tuned more to make them accurate. Then your read AFR will equal your commanded AFR.
