lean area around 2500ish rpms-2014 ctsv

[sgod1100]

I bet that VVE spike is just from my tune. And that was created by doing EQ error from the wbo2. So that is the wbo2 error being seen and trying to correct the issue. I bet if I tuned via LTFT it would not have as much of a spike. Pretty sure he just changed the injector data. You can download my original tune to compare.

ohhh gotcha, thanks

[JayRolla]

Found another one I had done for the lsa blower and 1050's that didn't have this problem - at least to my knowledge. I put all of the tables into Jay's. You'll probably have to retune the MAF or just plug it in and let the o2's correct for the quick drive... It's got to be something in the calcs that the ecm is seeing and testing for.

Don't think much changed with the issue with your injector data. Did a pretty good log with multiple throttles at different percentages and still get the same lean spike. Did a couple WOT in PE towards the end and still get the spikes there also. Very strange issue indeed.

[GHuggins]

This one has your MAF mostly dialed back in. Looks like it goes up to 7% lean right at 2500 even though I see nothing changing to tell it to right there. This one also has that different torque model, but don't think that'll fix it as I'm starting to believe it's something OS specific since so many don't do this.

Add as many more pids as you can to the channels. Torque management, airflow and fuel related primarily.

If the problem will stay there - hold constant pedal at 2500 too. Want to see if it's a rpm changing issue as the revs pass through it or just specific rpm area issue.

[GHuggins]

https://www.ctsvowners.com/threads/o...tumble.143730/

I found this thread with someone that seemed to have the same issue with a manual 6 speed car. They said the tuner fixed it by correcting the injector scaling. Right now I have my IFR at 50% of injector size and then doubled the stoich table to scale my injectors. I remember when I first installed my injectors I didnt scale them and maxed out the upper tables just to get it running. I dont know if I had the stumble then. Then I scaled them and maybe thats when the issues started. I need to look at some older logs but maybe this issue has to do with the scaling somehow.

I just read that whole thread. They say "injector scaling", but what I'm almost certain they're talking about is having the fueling dialed in which would work around the problem... It honestly looks like certain cars have certain OS's that are doing something right there.

[JayRolla]

This one has your MAF mostly dialed back in. Looks like it goes up to 7% lean right at 2500 even though I see nothing changing to tell it to right there. This one also has that different torque model, but don't think that'll fix it as I'm starting to believe it's something OS specific since so many don't do this.

Add as many more pids as you can to the channels. Torque management, airflow and fuel related primarily.

If the problem will stay there - hold constant pedal at 2500 too. Want to see if it's a rpm changing issue as the revs pass through it or just specific rpm area issue.

First off I just want to say thank you so much for taking time out of your day for helping with this. It is greatly appreciated. Looks like the issue is still present. It does only seem to happen when passing 2500rpm at say 25-40% throttle. If I pass that rpm with very light throttle its fine. Holding it at that RPM it seems to run at stoich. You did seem to get my maf dialed in because fueling is pretty spot on again. I added as many PID's as I could think of, was not exactly sure what ones you wanted to see.

[GHuggins]

So if you're holding throttle or very lightly passing through that rpm it's fine - just when passing through it heavily the problem is there if I understand it correctly. Torque was the only thing I've seen changing much in the logs - dips down right at the problem then goes back up. Was hoping that model would help, but it didn't. I assume the VE table has been dialed in with MAF failed? What happens if you run a stock VE table?

[GHuggins]

I think I've been looking at this from the wrong point of view. Let me ask this - did it feel better this last time cause it looked like a normal check (that shouldn't be happening with the settings the way they are) and because of the injectors it's causing a "larger" swing but at least this time it looked like the ecm was controlling it better...

[JayRolla]

So if you're holding throttle or very lightly passing through that rpm it's fine - just when passing through it heavily the problem is there if I understand it correctly. Torque was the only thing I've seen changing much in the logs - dips down right at the problem then goes back up. Was hoping that model would help, but it didn't. I assume the VE table has been dialed in with MAF failed? What happens if you run a stock VE table?

Yes that is all correct. And you can feel that TQ dip when driving. VE was dialed in with MAF disabled using EQ error. I have thought of slapping the stock VE table back in and starting over.

[JayRolla]

I think I've been looking at this from the wrong point of view. Let me ask this - did it feel better this last time cause it looked like a normal check (that shouldn't be happening with the settings the way they are) and because of the injectors it's causing a "larger" swing but at least this time it looked like the ecm was controlling it better...

It might have felt a little better. I was not paying close enough attention to the car manners as I was watching the wbo2 and trying to get a good log. I'll try to get a good run in the morning.

[GHuggins]

I'm pretty sure it's an exhaust test that shouldn't necessarily be happening or just an O2 sanity check. If you look at the last log you posted right after it happens bank to bank fueling changes then goes back to normal. It follows normal O2 testing characteristics. Problem is we've thrown in big injectors so now what should be small un-noticed swings are not only noticed but being felt. Might explain why it does it first thing in open loop too.

Just a theory I know, but what I'm seeing. Also when I tune these I tune in the O2's for the exhaust changes. Maybe why I haven't necessarily noticed it. Don't know?

This one has the MAF finer tuned and O2's changed.

[JayRolla]

I'm pretty sure it's an exhaust test that shouldn't necessarily be happening or just an O2 sanity check. If you look at the last log you posted right after it happens bank to bank fueling changes then goes back to normal. It follows normal O2 testing characteristics. Problem is we've thrown in big injectors so now what should be small un-noticed swings are not only noticed but being felt. Might explain why it does it first thing in open loop too.

Just a theory I know, but what I'm seeing. Also when I tune these I tune in the O2's for the exhaust changes. Maybe why I haven't necessarily noticed it. Don't know?

This one has the MAF finer tuned and O2's changed.

Would something like this also cause the spike at WOT when in PE? Tried your new tune and still has the issue. I can still feel the TQ dip, car feels like it loses power right at the spike and then power immediately comes back in. I then tried a stock VVE table and still have the same issue. The maf seems really dialed in now though. Here are two quick logs. Log3 is your latest tune file. Log4 is you previous file but stock VVE table.

[GHuggins]

O2's won't be while in PE. Don't know on that one. It's also not the MAF cal as different gears put it in different loads. Funny thing is I haven't found anything on a ZL1 doing this, but the manual CTSV's seem to be the only ones. I put some ZL differences into this one but again don't have hopes. I think the problem is still rationality check or something it's doing and the bigger injectors are throwing it off.

[PGA2B]

Greg- Mine is an auto. I sent you my last log and tune. But I have ID850's

[GHuggins]

Would something like this also cause the spike at WOT when in PE? Tried your new tune and still has the issue. I can still feel the TQ dip, car feels like it loses power right at the spike and then power immediately comes back in. I then tried a stock VVE table and still have the same issue. The maf seems really dialed in now though. Here are two quick logs. Log3 is your latest tune file. Log4 is you previous file but stock VVE table.

Is there a reason the fpcm stuff was changed? Pressure sensor and baro settings in particular?

[JayRolla]

Is there a reason the fpcm stuff was changed? Pressure sensor and baro settings in particular?

Those settings are from my stock tune. I have not touched anything under fuel system. I just compared to a stock tune from the repository for a 2015 manual and those settings are empty. I also notice a lot of other stuff has little small changes that dont match my stock tune. My car was 100% stock when I got it but for some reason some of my settings are slightly different on a lot of stuff you normally dont touch.

[sgod1100]

O2's won't be while in PE. Don't know on that one. It's also not the MAF cal as different gears put it in different loads. Funny thing is I haven't found anything on a ZL1 doing this, but the manual CTSV's seem to be the only ones. I put some ZL differences into this one but again don't have hopes. I think the problem is still rationality check or something it's doing and the bigger injectors are throwing it off.

that lean spot for me is definitely still present during PE too. I was wondering the same thing-if it was just us M6 guys, but PGA2B is auto so doesn't seem to be trans specific.

[GHuggins]

Those settings are from my stock tune. I have not touched anything under fuel system. I just compared to a stock tune from the repository for a 2015 manual and those settings are empty. I also notice a lot of other stuff has little small changes that dont match my stock tune. My car was 100% stock when I got it but for some reason some of my settings are slightly different on a lot of stuff you normally dont touch.

I went through the various different cals I had for the ctsv's. Looks like they changed the settings in 13, but your baro axis has been changed. I was even wondering if maxing out the inj flow table in the fpcm would make a difference?

[GHuggins]

that lean spot for me is definitely still present during PE too. I was wondering the same thing-if it was just us M6 guys, but PGA2B is auto so doesn't seem to be trans specific.

Specific rpm in PE? I may have overlooked it in PGA2B's log. Was waiting to hear back from him. Short of purposely putting in the wrong injector data and skewing things I'm not entirely sure on it yet. Wish I could get in and look at coding to see what's primarily different between these and the ZL's.

[sgod1100]

Specific rpm in PE? I may have overlooked it in PGA2B's log. Was waiting to hear back from him. Short of purposely putting in the wrong injector data and skewing things I'm not entirely sure on it yet. Wish I could get in and look at coding to see what's primarily different between these and the ZL's.

Same exact spot in PE...if I'm in a higher gear the lean spot will be more of a long hump since you are slowly passing through that 2600 rpm area. I MAY have a log showing that. I'll post it if I do

[JayRolla]

I went through the various different cals I had for the ctsv's. Looks like they changed the settings in 13, but your baro axis has been changed. I was even wondering if maxing out the inj flow table in the fpcm would make a difference?

What baro setting are you exactly talking about?