Fuel Trims +20%
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Fuel Trims +20%
Hey guys, my fuel trims are saying I'm really lean, car smells really rich, I've checked for vacuum leaks, I've found none, I've check for exhaust leaks, I've found none, I do have the P0133 & P0153 codes, I have new front Delco O2's, rear deleted, also have new Delco MAF, Car has LS6 heads an Intake, F14 cam, Lt's, it's a M6, besides the tune is there any thing els I should be checking??
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smells rich, can't go by that, especially if you have NO cats. If the trims are positive like that, can the tuner take a look and see? what is your idle MAP?
can you post the tune? or a scan log of the car?
can you post the tune? or a scan log of the car?
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Both banks,
MAF 8g/s
Inj PWM Avg B1 3.5 msec
Inj PWM Avg B2 3.5 msec
Rpm 850
BLM CELL 20cnt
Barometric Press 30 inHg
MAP 17 inHg
MAP VOLTS 1.1
Intake temp 158F
Coolant temp 189F
ST fuel trim B1 21.1
ST fuel trim B2 24.0
Spark adv 22 deg
MAF 8g/s
Inj PWM Avg B1 3.5 msec
Inj PWM Avg B2 3.5 msec
Rpm 850
BLM CELL 20cnt
Barometric Press 30 inHg
MAP 17 inHg
MAP VOLTS 1.1
Intake temp 158F
Coolant temp 189F
ST fuel trim B1 21.1
ST fuel trim B2 24.0
Spark adv 22 deg
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Unplug your maf as long as it doesn't have the built in iat sensor and see if your fuel trims come back to normal. If they do you either have a bad maf or air getting in behind the maf.
If they don't come back verify your fuel pressure is good. If it is have your tune checked.
If they don't come back verify your fuel pressure is good. If it is have your tune checked.
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The MAF that was on the car when I bought it was an all aluminum unit that looks factory but has no screen or divider in the middle, I was told that it was the problem, the new one I have is a newer plastic style Delco with the adapter wire on it, could this be the problem??
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OK. I don't find 50kPa-range unusual for anything with a
cam and a blower dragging.
A rich smell is likely high HC, which can come from either
rich or lean. The difference is, lean will sting (NOx) and
rich won't.
I'm still suspecting false trimming. Especially if it idles nice
after you reset the trims, and then it goes to crap over
a minute or two of sitting at idle. Do what you can to
check that. Try turning off LTFTs and let STFTs do the
work, because they reset on every cell transition; high-
idle it to get the sensors hot, then drop to regular idle
and see how the STFTs creep, whether they are happy
for a bit and then head north as the pipes cool.
cam and a blower dragging.
A rich smell is likely high HC, which can come from either
rich or lean. The difference is, lean will sting (NOx) and
rich won't.
I'm still suspecting false trimming. Especially if it idles nice
after you reset the trims, and then it goes to crap over
a minute or two of sitting at idle. Do what you can to
check that. Try turning off LTFTs and let STFTs do the
work, because they reset on every cell transition; high-
idle it to get the sensors hot, then drop to regular idle
and see how the STFTs creep, whether they are happy
for a bit and then head north as the pipes cool.
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i beve the LT FT are turned off already, they never moved off zero, i just tried warming it up, kept rpm's up high and reset ST FT to zero, they started creeping up immediately while still at high idle, i guess next is back to the tuner.
#19
If you put it in SD mode it will not look at the MAF and it should not have the Fuel trims you have. If it doesn't clear it up then it is something more. Check your TPS also for at idle it should be close to .67 volts that will affect alot of things also.
With your Fuel Trims are +20% it is running lean. And with it running that lean it is trying to add large amounts of fuel in a short time. Is probably why there is such a large movement from rich to lean. BLM's are really made to do small adjustments actually. I'm willing to bet that Your VE tables are not set to well.
I suggest tuning SD mode first. Then if you want to use closed loop.....tune that afterwards.
But remember to lock it into SD mode.......you can't just unplug the MAF. In LT1 Edit there is a switch on the first screen when you select the file you want to use. I shows your VIN and anything else that is on or off. VATS, EGR, etc. And then also under the fueling table I put 155 in both slots under the closed loop enable temp. Christian Millard suggests 255 but I can't put that in LT1 edit....... 150 is max. But that is like 300+ F degree's anyways. Then I go in and shut the PO102 and PO103 in the hardware verifcation so it wont trip the Hi and Lo MAF codes.
Some will argue that closed loop doesnt use the VE tables, I read of someone that had tested that and found that when you zero out the VE tables that closed loop throughts fits. It supposedly uses it as a referance. I havent had time to test it yet.....but I am going to just to verify it. And arguing case of tuning SD mode is that if a sensor goes bad in closed loop your power and drivablity will not be effected anyways.
There are some modded cars that all they can run is the SD tune.
With your Fuel Trims are +20% it is running lean. And with it running that lean it is trying to add large amounts of fuel in a short time. Is probably why there is such a large movement from rich to lean. BLM's are really made to do small adjustments actually. I'm willing to bet that Your VE tables are not set to well.
I suggest tuning SD mode first. Then if you want to use closed loop.....tune that afterwards.
But remember to lock it into SD mode.......you can't just unplug the MAF. In LT1 Edit there is a switch on the first screen when you select the file you want to use. I shows your VIN and anything else that is on or off. VATS, EGR, etc. And then also under the fueling table I put 155 in both slots under the closed loop enable temp. Christian Millard suggests 255 but I can't put that in LT1 edit....... 150 is max. But that is like 300+ F degree's anyways. Then I go in and shut the PO102 and PO103 in the hardware verifcation so it wont trip the Hi and Lo MAF codes.
Some will argue that closed loop doesnt use the VE tables, I read of someone that had tested that and found that when you zero out the VE tables that closed loop throughts fits. It supposedly uses it as a referance. I havent had time to test it yet.....but I am going to just to verify it. And arguing case of tuning SD mode is that if a sensor goes bad in closed loop your power and drivablity will not be effected anyways.
There are some modded cars that all they can run is the SD tune.