Very high O2 correction

gibbstroy

Member
Jan 12, 2018
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Allen, TX, United States
I have another noob question. Im seeing very high O2 corrections in the 20's at WOT after changing 160# to 210# injectors and making the changes in XFI 2.05. Its able to hit the right afr's but its on the ragged edge. With the 160's still installed, O2 correction shows high on a 1/4 log dated 10.28.18 but not as high.

Here are the only changes made after the injector change:
1) fuel calc parameters changed to 210
2) Cranking fuel vs coolant temp= multiplicative trim of 68
3) AE fuel vs TPS roc= multiplicative trim of 68
4) AE fuel vs MAP roc= multiplicative trim of 68

My TPS shows low on the logs, but Im sure Im just not pressing the gas hard enough to compress the carpet below it. With the engine off and concentrating on pressing hard enough, TPS reads 92 or so. What Im looking for is how to get the O2 sensor under control the correct way before starting to get the VE table adjusted. In other words are my changes for the 210's sufficient or should I move on to the VE table?

Any advice is appreciated!
 

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gibbstroy

Member
Jan 12, 2018
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Yes sir it is. I LOVE this thing! The 160 injectors were failing so I went to 210's. Im not logging fuel psi yet, I will in the future. Im just trying to make sure I clean up the tune now that injectors and elevation have changed from when Kevin had it.

BTW the fuel pressure gauge is keeping up with boost as it should, touching low 80's under full boost.
 

norbs

doing more with less
May 25, 2001
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You voltage could be dropping under WOT and if your injector offset values are off it could have some effect
 

turbo nasty

Turbo Dojo / MNTR
Jul 19, 2001
8,237
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Always log battery volts.
Kevin had a issue with the car running out of fuel as well when trying to break into the 9's.
For starters check every fuel filter for cleanliness as well as all electrical connections at the fuel pump/BAP. Also, check check the fuel % tables ...i.e.- fuel vs. coolant temp, vs. IAT, etc
 

gibbstroy

Member
Jan 12, 2018
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Allen, TX, United States
Im close to upgrading the pump. A lot of things point to the Eliminator not quite doing it even though its rated for almost 1000hp on e85. Thanks for the tip!

And thank for your service! My brother is retired USAF as well.
 
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gibbstroy

Member
Jan 12, 2018
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Allen, TX, United States
Just checking my math... Using BCFS for boosted e85 (.84-.91) for roughly 900hp, fuel requirements come out to 1.8 to 2.1 gpm, depending on 30ish boost level. The Eliminator is advertised to provide about 2.5 gpm for 70-80psi at 13v. It doesnt seem that there is such fuel starvation to require over 20% correction from the O2? Im not trying to be argumentative, just trying to understand.
 

turbo nasty

Turbo Dojo / MNTR
Jul 19, 2001
8,237
434
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St Paul, MN
Just checking my math... Using BCFS for boosted e85 (.84-.91) for roughly 900hp, fuel requirements come out to 1.8 to 2.1 gpm, depending on 30ish boost level. The Eliminator is advertised to provide about 2.5 gpm for 70-80psi at 13v. It doesnt seem that there is such fuel starvation to require over 20% correction from the O2? Im not trying to be argumentative, just trying to understand.
I think 2.25 -2.3 gpm is close. I havent looked at your logs so cant see your tables
 

ITSAV6

It's my Granny's car!
Nov 13, 2001
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sogaturbobuicks.4t.com
I am assuming that's 92% tps, can you recalibrate the range? The XFI is correcting the A/F at wot, so can you turn the self tuning on in the range it is adding all the fuel and see if it corrects the fuel table?
 

gibbstroy

Member
Jan 12, 2018
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Allen, TX, United States
I am assuming that's 92% tps, can you recalibrate the range? The XFI is correcting the A/F at wot, so can you turn the self tuning on in the range it is adding all the fuel and see if it corrects the fuel table?
Thanks for the reply! Yes, the 92% was the TPS with engine off after recalculating. And I actually have been running in learn mode hoping it would correct the fuel table at WOT. But it just keeps adding 20%. If I manually add 20% to the cells, they are in the 130's which is too high. Scratching my head.

I contacted Aeromotive about possible starvation and their response was this:

Presuming your Eliminator pump is in good shape, and is plumbed and powered properly, you should be good to about 950-980 FWHP on E85. That said, if you don’t want to take any chances you can certainly upgrade to a higher flow pump, and we offer 3-steps above the Eliminator:

Of course I take that with a grain of salt.
 
Last edited:

NY Twin Turbo

All the good stuff.....Times 2.
Dec 10, 2014
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Silly question. But have you looked through all of the tables in your tune? I mean even the ones you don't use. Like individual cylinder correction, all the other you don'rt visit often? Power adder configurations? Just everything?

Just wan't to be sure you didn't miss anything simple. I know I have.
 

gibbstroy

Member
Jan 12, 2018
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Allen, TX, United States
Silly question. But have you looked through all of the tables in your tune? I mean even the ones you don't use. Like individual cylinder correction, all the other you don'rt visit often? Power adder configurations? Just everything?

Just wan't to be sure you didn't miss anything simple. I know I have.
Not silly at all. That’s primarily why I started this thread. I’ve looked through the whole tune but being new to FAST I can’t be sure I’m not missing anything.

The only changes I’ve made are the ones Cal describes in one of his videos.


Sent from my iPhone using Tapatalk
 

gibbstroy

Member
Jan 12, 2018
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Allen, TX, United States
Is it actually changing the cells when it adds 20% or is it just correcting the A/F and not saving it in the individual cells?
I really never notice any cell changes, even after verifying that learning is still on. The learning light in the edash comes on as well. My best guess is that it’s just adding fuel but not correcting ve’s.


Sent from my iPhone using Tapatalk
 

ITSAV6

It's my Granny's car!
Nov 13, 2001
2,149
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Ocilla,Georgia
sogaturbobuicks.4t.com
“When I spoke with one of the higher up guys at FAST recently via email, his best advice for simple street tuning was to start with the recommended settings for the self learning sensitivity and tune in the really rough spots by hand in the VE table to help it out; then as the tune is learned in, tighten up the sensitivity. You get the major stuff dialed close, then let the learning polish off the fine tuning as you drive (or you can fine tune it yourself if you like”
Found this on another forum.....
 
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