So the time i took in tuning my VE map perfectly and MAF as well as WOT went in vain..... When i went to florida everything was fine, until i decided during an off-day to clean my CAI filter. Well I took everything apart, examined my tubing and noticed the MAF sensor screws were loose and wouldnt attach right to the point i could just pull them completely out or in. So for a temp fix (and also because home depot was closed) i wrapped some duct tape around it and sealed her up.

So driving around i noticed i was getting 20 mpg highway. Hooked up my handy dandy hptuners and low-and-behold my VE table is screwed, MAF screwed...all rich as hell. Now i thought the VE table was strictly computer... not sensor-based. Perhaps im tuning it wrong? I set the MAF to fail at 0, TPS to 100% etc and tuned her back to where i wanted. Fixed my MAF frequency (close) to where i want it.

However when i hit WOT now my AFR drops to 10.0
Ive also noticed under normal cruising at 50-80 my AFR sticks to 14.0 on average. My guage need recalibration? Anyone come to this issue before? Thanks.

 

update:

loaded my old tune after coming back to GA and everything is fine short of my MAF and PE enrichment(understandable considering the maf looseness). Very frustrating.

 

yes your VE is gonna be fucked if you tuned it with a leaking maf sensor. more air was coming in. honestly, dont waste your time trying to get your VE perfect. it is only referenced when the maf fails and under some weird low rpm situation i cant remember.

 

actually the maf and ve talk to each other alot during closed loop. Especially under constant states. Try roughing in your VE table and your mileage will go up tremendously!

Just by tuning my VE table i went from 20ish mpg to 36. Although when i did my maf tuning and then blended it went to 33-34.

Just to find out if i was b.s. i kept it in open loop (strictly maf) and it went to 28.

Anyway, its all tuned right and looks good. I had no idea that if it leaked you would get so hosed.

Also it really isnt good to NOT tune your VE, since once you hit WOT the maf goes off the last value of your VE before the point of open loop. Which can definitley pop a piston if your not careful. I was looking in to the GM pcm calculations last week about it.

 

My screws messed up on my Injen CAI as well last time I cleaned the MAF and filter. I just re threaded it and put some bolts which should of been used in the first place instead of those shitty ass screws.

 

that may be my issue...hhmm
I need to check the filter....

 

ok so i was monitoring my car again as i usually do to make sure everything is clean and tidy.... and ofcourse today was 100 degrees out... my IAT1s were 102 and IAT2s were 140ish even going down i-85 home.

Something i just noticed.... and is pissing me off

my AFR shows that i am always 1+ AFR RICHER than commanded..... so if i command 11.5 i generally get 10.3 or some crap.... infact even during early WOT i get 11ish AFR when im commanding low 12s.

My trims are saying "your a lean bastard" especially on the top end i see +9s yet my AFR is stating "your a rich bastard" and giving me these 10s.

Short fuel trims up top are 0.

Im at a fricken loss on this one, since i didnt realize my narrowband would be so whack from my wideband.

I recalibrated the wideband before coming home because when i punched it TO work i saw it dip down to the 10s.

20.5 was the oxygen reading before i left so i know my wideband is fit as a fiddle. Anyone have any ideas what to go with?

I really dont feel like fighting with my trims...is there a way to adjust them? maybe replace my narrowband or use the narrow band simulated in place of the stock sensor? Really erking me.

 

ballsy to command 12's for WOT

 

only from around 3k rpm under WOT

bump for questions unanswered

 

retune your MAF...
if you're concerned about your trims, you can make a histogram and track it them fix the cells that need to be fixed.

 

i only know of the HZ cells for the maf.... not something like the VE for the maf.

Are you saying adjust my VE table to compensate?

BTW my maf is around .5 - 2.5ish lean across the HZ range.
LTFTs are also lean....

but AFR=rich?

bump for ideas and tuner's experience

 

ok it must have been the 100 degree weather since going to work and logging everything is spot on.....

Either that or my car has phantom sensors that like to screw with me.

LTFTs are +/-1 (mostly 0s) MAF within .5 of my trims. and AFR was only slightly leaner than commanded. I really dont want to have seperate tunes for different weather patterns.

 

ugh... look newbie,

1. you can control when your ecu references VE by setting the dynamic airflow enable/disable rpm. I and another member made our VE chart look like a pair of **** and the car still ran the same. as long as your maf does not fail, you wont blow up your engine. if you have AFR error, it is most likely in your MAF table, assuming your injector offsets are correct.

2. your fuel trims do not register when in PE. thats why they read "0"

3. you cant recalibrate your wideband (LC-1) while its in the downpipe. it has to be free air calibrated.

4. it is not necessary to have perfect fuel trims. 2.5% is well within the acceptable range. trims are there to compensate for variances. don't over-tune, let them do their job

5. yes, you should have separate tunes for warm and cold weather.

 

wow i love you too.

this is true, however i dont want to know what will happen when/if your maf/maf sensor fails...im considering mafless tune to avoid this crap

yes this i know, it is enabled in the TPS

after 8 hours you can recalibrate it in the downpipe. Ive done it many times and have had the same results as if i pulled it.

The problem was running rich on my AFR (9s) yet the maf/ve were stating lean... this could very well be the calibration of my wideband but it was stoich during cruise.

die in a fire!

lol was just kidding but anyway, i was hoping there was a way to modify the maf vs the IVT temps to avoid your #5

btw thanks for pointing out things that could have screwed me if i was truely naive. (seriously)

 

the aut0ritiez will come looking for you if my house burns down tonight

as of now, no one has come forward with any method of tuning MAF vs intake valve temp to prevent this.

your fuel trims will usually keep you near stoich even if your w0t afr is fuct, unless you have major failures in your injector maps or other areas of the tune.
btw, what do you mean by "enabled in the tps"?

 

eh we spoke about it before.... my tps was 95% for WOT and now its 35% for obvious reasons

eg: if i were to tune my VE table, i set TPS to 100% for PE enrich.

problem i WAS having was that it seemed my wideband and my narrowband were fighting with each other... however with the same tune and under diff weather conditions it all was spot on.... it was frustrating at the time.