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Lean'er wideband #s in colder temps

MellowVR4

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So today I took my car out for a drive, Doing a few WOT pulls and what not. I noticed that my WB gauge was reading at like 13.5 while I was getting on it, Granted that today was about 25 degrees outside with the windchill even colder, Could this cause the car the lean out cause its so cold out? Didn't hit knock at all or anything like that. Just wondering if this is normal in colder weather.
 

AnotherNewb

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Cold air = denser air thats why it seems like your car runs better when its cold out because its getting 'more' air. Depending on your tuning set up and a working O2 sensor, your ECU should compensate with its short term and long term fuel trims, just gotta drive it a little bit so it can learn.
 

MellowVR4

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Yeah she's liking the cold air alright /ubbthreads/images/graemlins/grin.gif
 

4thStroke

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Fuels trims dont affect AFR under open loop.

Depending on the tuning system and what you are using to compensate for air temperature, your air temperature compensation may not be working correctly.
 

bmxr152

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Also if your running a 180 t stat it might not get over 190 which is learning mode i know here it has been.in the 20s in ther morn ing and i have been running really lean until i adjusted my coolant offset on dsmlink. My coolant temps were 175/180. So i can say yes it could possibly happen. It stumped me for a while. Fuel pressure was good. Injectors good. Everything except i would just lean out under light to medium load.
 

manikbastrd

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Quoting MellowVR4:
So today I took my car out for a drive, Doing a few WOT pulls and what not. I noticed that my WB gauge was reading at like 13.5 while I was getting on it, Granted that today was about 25 degrees outside with the windchill even colder, Could this cause the car the lean out cause its so cold out? Didn't hit knock at all or anything like that. Just wondering if this is normal in colder weather.



If I am not mistaken, usually aren't WOT pulls closed loop (or open loop I always confuse the two) meaning that the settings that are dialed in are the settings that are dialed in, unless your tuning software receives input from an IAT?
 

MellowVR4

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I think its at open loop, not sure either tho.
 

diambo4life

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Edmond, Oklahoma
"Closed" ECU depends on O2 sensor feedback to control AFR. Open - ECU looks at predefined maps for load/rpm. So when you are at WOT, you are in open loop although when I used to have dsmlink V2.5, I ran my Talon in forced open loop. This helped me sort of force the ECU to run the car leaner (where it normally uses O2 sensor feedback) nd my gas mileage especially on E85 was greatly improved. Another reason your car could run leaner in much cooler AITs is colder air = more airflow per unit time and if your fuel pump or fuel system can not handle the airflow (if you were already at it's limit) the vehicle will run leaner.
 

MellowVR4

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Bringing this one back because I have a few questions.

First: Would not enough voltage feeding the wideband make the reading inaccurate?

second: Would a miscalibrated sensor show a 13.5 at WOT with out any knock?

Reason why I'm asking these questions is because I've been DD my galant and have noticed this going on with my WB. Originally When I got tuned Running the big 16g everything was fine and the wideband would read 11.5 AT WOT at about 17/22 psi with 750cc's. Now that I have 1000cc with a 60trim at about 17-18psi Im getting 13.5 at WOT??? I have to confess that When I switched to this turbo in I didn't take my wideband off to recalibrate it. Do I have to? As far as I know Im still not getting knock, I have not logged anything but I will probably later today. Any help would be great! Thank you.
 

ghostinthevr4

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To put it simply it sounds like you need to retune it. If your wideband is the type that does free air calibration then it wouldn't hurt to do it.
 

MellowVR4

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I was afraid of that. Do you think when I add meth 50/50 to the mix I could get the 11.5 without a tune? not trying to cheap out but /ubbthreads/images/graemlins/dunno.gif
 

ghostinthevr4

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I'm not sure I don't use meth, anytime you change your injectors a retune is most likely in order not only that you changed to a bigger turbo. You know the turbo is flowing more than your 16g because it's running leaner with bigger injectors, your probably gonna have to add more fuel.

What are you tuning with?
 

MellowVR4

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V3 Lite
 

MellowVR4

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Im gonna try and do this my self, Don't wanna cough up 450 for a retune /ubbthreads/images/graemlins/banghead.gif.

Going to try to recalibrate it first, if that doesn't work then Ill try and add more fuel on link. Im gona SOUND stupid but I don't know how to add fuel lol, Have to read those wiki things again.
 

ghostinthevr4

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Don't beat yourself up, read it till your eyes bleed and take small steps. Make small fuel changes and see if the AFR's respond the way you want them to, it might take some time but eventually you'll get it.
 

MellowVR4

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Yea man, I just get weird when I get to the tuning part. don't know if im doing it right or not /ubbthreads/images/graemlins/dunno.gif I know I can get used to it, but just have to read read and READ...
 

MellowVR4

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Milwaukee, Wi
Just a 2g maf.
 

MellowVR4

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Milwaukee, Wi
So, When I wanna add fuel do I just go to the fuel settings and add % on the RPM'S which im running lean on? That would be the obvious I think /ubbthreads/images/graemlins/dunno.gif
 
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