AFRs fine at WOT then dead lean randomly?

[ziggo0]

I'm trying to figure out if my wideband is acting funny or my fuel setup. For now, I'm on 550cc injectors and an EVO 8 Fuel pump. Stock FPR. Base set with a MAF-T, dialed in with a SAFC. Wether the SAFC is 0'd out or not, I'll go to WOT in 3rd and it will slow 10.0 to 10.5, then just 19 out of nowhere - yet when it hits 19 the car doesn't feel any slower or spudder or act funny. Any ideas?

 

[1996dsm]

i have the same exact problem, and my AEM WB is only like 2 months old.

 

[turboglenn]

Did you mount it according to the "guidelines"? As far as being at least 12" from the 02 housing/turbine area, and no more than 36" (3 feet) from the head? Also, possible you could have a leak in your flex section of the down pipe.

But Really<i'd pay attention if it's always at a certain RPM and or boost level, because if so that's possibly your fuel system running out.
Sounds like something is wrong but for the most part the AEM widebands seem pretty reliable from my experieces with them and the sensors (unless subjected to abuse or mounted wrong) usually last quite a while. If it never acts up or acts oddly any other time then i'd say you're running out of fuel.. If it stays rich at the same RPM/boost in 2nd then it's even more likely you're runnin out of fuel. 3rd Gear is loading the engine harder requiring more fuel to to keep up with the demands in airflow (remember turbos are really load dependant,which is why on larger turbos they can't make their full boost in the lower 1st and 2nd gear, because the car either looses traction and drops load or revs out before it can be loaded hard enough to spool all the way up.

Try 4th, same boost, same AFC settings, and see if this happens earlier or at the same RPM. Being that it does it in 3rd everytime no matter the AFC setting shows it's not really random, but under higher loads.

 

[ziggo0]

It's actually a wideband from 14point7.com - I contacted the maker to see if he has had any problems like this. I decided to take my fuel outta the equation, walbro, afpr and 1000's are going in today.

 

[turboglenn]

cool, once those are in you should be good on fuel but i after lookin at your mods i see you have eprm and evo scan you should be able to pull some logs, post em up here and get a diagnosis without spending moeny on parts. the AFPR isn't gonna change it really, and i ran a stock FPR on a wally 255 for many many years without runnin into issues. but if ya got it, might as wel run it right

now that i've read your mods list I can see that you probably were runnin out of fuel with 550's and evo pump if you were pushin that 20g hard (but you didn't say what boost levels you were runnin or if it was just pump gas or ethanol/e85)

Let us know how it goes after the fuel upgrade!

 

[ziggo0]

cool, once those are in you should be good on fuel but i after lookin at your mods i see you have eprm and evo scan you should be able to pull some logs, post em up here and get a diagnosis without spending moeny on parts. the AFPR isn't gonna change it really, and i ran a stock FPR on a wally 255 for many many years without runnin into issues. but if ya got it, might as wel run it right

now that i've read your mods list I can see that you probably were runnin out of fuel with 550's and evo pump if you were pushin that 20g hard (but you didn't say what boost levels you were runnin or if it was just pump gas or ethanol/e85)

Let us know how it goes after the fuel upgrade!

Yeah that is a little out dated. I got the wally and afpr on there now, no changes - so it wasn't the fuel pump acting odd. I'm only at 10psi on the 20g due to a fresh motor/break in - but it wants to creep - still wouldnt explain why it goes dead lean - except now it does it while cruising...I'm leaning towards a shot sensor. Once I get my head back on (CAMS!!!) I'll go pickup a new wideband sensor.

 

[turboglenn]

Yeah that is a little out dated. I got the wally and afpr on there now, no changes - so it wasn't the fuel pump acting odd. I'm only at 10psi on the 20g due to a fresh motor/break in - but it wants to creep - still wouldnt explain why it goes dead lean - except now it does it while cruising...I'm leaning towards a shot sensor. Once I get my head back on (CAMS!!!) I'll go pickup a new wideband sensor.

yea, culd be shot sensor... when they go bad, a few times i've had them start going to one end of the scale or the other and stayin there for a minute and then being okay and finally they just go full lean or rich as soon as they warm up... and if WOT or cruise even if you don't feel the car's power change going from 10:1 to 19:1 i'm bettting sensor