Stalling & AFR Question

['14 Shelby]

Quick history...A little over a year ago, I had TVS installed with other mods. It was dyno tuned by (a reputable tuner) and has had stalling issues ever since. The stalling occurs in almost every case when decelerating in neutral. There were several revised tunes sent to adjust the 'decay rate' for the idle and its only been marginally better.
I plan on spending another $500-$600 on a dyno tune at some point to address this but not right now.

My question is regarding the AFR. Yesterday when this happened I was looking at the AFR reading on the dash. It read about 10.6 and 10.0 when it finally stalled. How reliable is this number?

 

[CSG]

What do the STFT's look like when it is acting up?

 

['14 Shelby]

What do the STFT's look like when it is acting up?

Sorry whats "STFT"?

 

[hitmix300]

Short term fuel trim. Log both of them

 

['14 Shelby]

Quick history...A little over a year ago, I had TVS installed with other mods. It was dyno tuned by (a reputable tuner) and has had stalling issues ever since. The stalling occurs in almost every case when decelerating in neutral. There were several revised tunes sent to adjust the 'decay rate' for the idle and its only been marginally better.
I plan on spending another $500-$600 on a dyno tune at some point to address this but not right now.

My question is regarding the AFR. Yesterday when this happened I was looking at the AFR reading on the dash. It read about 10.6 and 10.0 when it finally stalled. How reliable is this number?

Short term fuel trim. Log both of them

I appreciate the input but I was not data logging, simply made a quick observation on the dash. I guess i'd have to data log to get better feedback on here? or just wait to retune

 

[hitmix300]

I appreciate the input but I was not data logging, simply made a quick observation on the dash. I guess i'd have to data log to get better feedback on here? or just wait to retune

Data logging should be mandatory for any tune or revision, IMO. You'll definitely have to datalog so we can try to see what happening.

 

['14 Shelby]

Data logging should be mandatory for any tune or revision, IMO. You'll definitely have to datalog so we can try to see what happening.

LOL - Readers Digest version of the e-mails from the reputable tuner
me - "it stalls under decel"
them - "i'll e-mail you a new tune to adjust only the idle"
me - "I loaded the re-tune and it stills stalls"
them - "I've updated the tune for idle only"

repeat 4-5 more times and of course it still stalls. tuner said I have vacuum leak, installer said its the tune, there were no leaks. Had a diff place confirm no vacuum leaks in April. Guess what? My F'n car still stalls

 

[CSG]

Fairly common complaint but not with a TVS...

 

[mebcop]

Data log.... impossible and inefficient to solve without knowing exactly what is going on. Your tuner should have told you that....

 

['14 Shelby]

Data log.... impossible and inefficient to solve without knowing exactly what is going on. Your tuner should have told you that....

Of course but my tuner did what he had to do when he had to and got his pay and that was it. It took like 3-4 weeks just to get a response to my problem. That's the extent of my bashing on here. Obviously I'd never recommend this tuner although many people use them.

 

[Vert]

Sounds like its running pig rich. I have compared the instrument AFR gauge to my aeroforce and it runs within a .1-.20 of each other. My tvs AFR runs around 11.3 under WOT.

 

['14 Shelby]

Sounds like its running pig rich. I have compared the instrument AFR gauge to my aeroforce and it runs within a .1-.20 of each other. My tvs AFR runs around 11.3 under WOT.

Thank you. This is the kind of answer I was hoping for. Just wanted to know if the dash gauge has any validity. I appreciate the other input as well.
I'll data log in hopes to confirm

 

[mebcop]

The fact that it's running pig rich isn't the problem. WHY is it running pig rich. Is it commanding pig rich, or is it going pig rich and not being able to lean it out enough. Is it just one bank going VERY rich, or both. So much more to it. I'm sure the tuner didn't command 10.0:1 AFR's at idle.

 

['14 Shelby]

The fact that it's running pig rich isn't the problem. WHY is it running pig rich. Is it commanding pig rich, or is it going pig rich and not being able to lean it out enough. Is it just one bank going VERY rich, or both. So much more to it. I'm sure the tuner didn't command 10.0:1 AFR's at idle.

Only during decel and maybe 1 or 2 out of ten times it actually stalls