Fuel trims

[eski]

sup,
so im trying to understand fuel trims using my logger.
i know im rich at idle but what should the low, med, high and o2 trims be on a stock 1g.
should they always be the same or should they fluctuate at all.
is the lower the number the richer it is?
does anyone know of any good articles about fuel trims?
thanks
Dave

 

[MY1GDSM]

I'm not sure about any articles about fuel trims

But The way you trims work Are that Say you Low trim is at 81.2 (thats as low as it will go) Then you Idel is to Rich and the Ecu is pulling as much fuel as it can out, Basicly what you want is all the trims to be at 100 but they will change +/- say anywere from 5% to 20%or more depending on how you are driving wether you take a long trip on the freeway or are flooring it stoplight to stoplight

Each trim is is @ a diferant Airflow say -- Below 88hz is the low trim, 88-180hz is the medium trim, and 180-400 is the high trim so Basicly if you watch what your FTo2 Trim and say while driving in 3rd slowly pulling more and more and at 200hz your Fto2 starts to drop below 100 to Say 70 then you do that a few mor times till your trims start to change you would see the Ecu Pulling the mid trim Down.

You said you are runing rich You should Update you Profile with some info And Everyone could be of more help

 

[eski]

thanks for the reply,that helps!

 

[eski]

yeah i know im rich at idle probably due to a leak.
just wanting to know where they should be at after ive fixed my leaks.

 

[MY1GDSM]

What do you mean by LEAK?
Also what are you using to Tune with?
and Again I/we could be of more help if you Updated/posted your Car info.....

 

[eski]

sorry i mean i have a boost leak, probably more than one.
i can hear one with my car running.
my ftrl is 81.12, ftrm 101.40 and ftrh 106.86. some pointed out to me that i was rich at idle.
i was also getting quite bad knock under wot but have since tightenned my connections before my turbo so that seems to have gone.
My car is completely stock, i just have a k&n filter with air can hack, boost gauge and logger. im planning some mods this summer but im wanting to get my car running nice.

 

[Turbo Talon DL]

You think your fuel trims are bad? Check this out: FT low:139
FT med: 122
FT high:126

It could be my cams and possibly bad valve guides too. The car runs fine. No EGR or anything like that and no evap canister. Mods are in profile. Cams with old style afc. I may crank it up past +5% to see if they get any lower. My spark plugs have barely changed color. The white insulator around the center electrode is still white with a little black/grey coloring. 9:1 compression too.

I adjusted the knobs on the old style S-AFC to +15 at 800, 2400, and 4000 RPM ranges and the FT low fluxuated from about 118-135% but always moves now. When I held RPMs at 1500 it richened up but when I let it idle, it would lean out.

 

[Turbo Talon DL]

You think your fuel trims are bad? Check this out: FT low:139
FT med: 122
FT high:126

It could be my cams and possibly bad valve guides too. The car runs fine. No EGR or anything like that and no evap canister. Mods are in profile. Cams with old style afc. I may crank it up past +5% to see if they get any lower. My spark plugs have barely changed color. The white insulator around the center electrode is still white with a little black/grey coloring. 9:1 compression too.

I adjusted the knobs on the old style S-AFC to +15 at 800, 2400, and 4000 RPM ranges and the FT low fluxuated from about 118-135% but always moves now. When I held RPMs at 1500 it richened up but when I let it idle, it would lean out.

I made them all change. The low seems to always be in the 130% range but everything else is within 95-115%. The car doesnt seem to really run much differently. It may be hurting my gas mileage now though.