ECU not responding to fuel tuning

[Cirus_93TSI]

im getting pretty pissed off at my car, im feeling like the data logger i bought was nothing but a waste of money, since it doesnt help the slightest bit with tuning my car.

as my mod list says, im running a 16g w/550s and a 2g MAS w/lower honey combs removed.
so my mid and high fuel trims are fine, o2 stays in closed loop when cruising between 2k and 4k rpm. the problem is my idle, my low fuel trim stays pegged at 139%, even though my 800 rpm setting on the afc is at +5. and regardless of how much i richen my fuel at idle the o2 trim stays pegged above 160 and the low trim stays at 139%.
the o2 trim does not show any reaction to my adding more fuel, unless i i go higher then +20 on the afc, at about +27 the o2 trim hits about 100, but the low fuel trim will not change(im not going to go to +35 to see if it changes, i know it shouldnt be that high). i think we can all agree that i should not be anywhere near +20 with 550s, even with the semi-hacked 2g mas.
iv sat in my car, with it fully warmed up for over 5 minutes, 3 different times today and i can not get the damn idle right. the low trim will not change and the o2 will not stay in closed loop. the afc is hooked up correctly, the karman reads on both my afc and my logger, and i wired in the safc v2 wiring harness 4 days ago since someone broke into my car and stole my safc v1(but left the wiring harness that has 10 pins instead of the 11 the new acf has), so im positive everything is hooked up correctly.

iv reset my ecu twice already today, and when i do the 02 trim stays at 100 untill i tap the gas, then immieditaly pegs at 167. the low fuel trim does not change regardless of the o2 trim.

what i dont understand is why everything was fine for 2 days after i put my new afc in, and now out of nowhere it idles like crap and the low trim and o2 dont read what they should. i even put a bottle of fuel injector cleaner in thinking my injectors might be clogged up from sitting unhooked under my hood for a month while my jdm longblock got put in, and it didnt do a damn thing but make my car spit a backfire out earlier today(which it has never done before)

if anyone thinks they know what the problemn is i wole appriciate a response, cause im about tired of throwing money into my car and it not getting any faster cause it wolnt run right

 

[nine5raptor]

Originally posted by Cirus_93TSI
i think we can all agree that i should not be anywhere near +20 with 550s, even with the semi-hacked 2g mas.

Im not surprised you need at least that much if not more. I had to richen my idle that much on stock injectors and on my 580's with a non-modified gm maf.

You need to give the car more time to adjust as well. Did you drive around for at least 20 mins for the trims to update after making changes?

 

[kpt4321]

Why are you running a hacked 2g MAF? That's not a good idea, there's no reason for it.

With a hacked 2g MAF and 550's, I would expect a lot of positive correction, expecially at idle.

Like Chris said, reset the ECU and tune from there.

You're best off if you put the honeycomb back.

 

[Cirus_93TSI]

if i had the lower combs i would put them back in, but the car had the 2g mas on it when i bought it, and didnt come with them in.
earlier i drove 15 min home from work and no changes, and the trims usually change within a minute. i just went out and started it up again, and sat in the car for about 6 minutes with the o2 trim pegged at 167 before the fuel trim finally jumped up from 100 to 139% again. i richened it up to +20 at idle and the low trim came down from 139 to 133%

but what i dont understand is that the car ran fine with the 550s and 2g mas at +7 to +12 idle for weeks. and it ran fine on +7 idle for 2 days after i put my new afc in. so i throw some injector cleaner in thinking they were a little gummed up from sitting exposed for the entire month on january, hear a backfire, and then my car needs twice as fuel enrichment at idle as usual. i just dont understand why i need more fuel all a sudden, trims were fine 2 weeks ago on the previous settings

im going to try it with laround a +25 setting and take a cruise to see how it runs. while were on the subject, what should my high settings on the afc be with my set up? should i be in + settings across my high afc map? or should i need less fuel because the fuel pressure goes up and the injector pulses change?
right now i have positive settings to stay at or around .90 o2 voltage, but i dont know if this is right cause the car doesnt feel as fast as it should. even on the low boost im running it should be faster. some days it will feel somewhat fast and others it will feel even slower then usual. im going to get dyno time to tune it but i need to have my dead knock sensor replaced before i do that.

 

[nine5raptor]

Your high won't be near as rich as your low. The thing with removing honeycombs on the 2g mas's is it makes the calibration curve non-linear. It is more off at low airflows than it is at high airflows.

With that being said, my corrections for idle and high airflows are different by 20% (leaner on the top end).