One second lean spike after shift Cobalt SS/SC

[TiCPU]

I really don't know what is going on on this, first I though I was really low on fuel and injectors really had no gas to inject, so I filled it up and still the same.
After shifting from anything above 4000 RPM, the shift goes well, then I floor it back and the car jerks, I look at the log, it happens just after the car switch from 14.7 to 11.5, when commanding 11.5 I get:
100% throttle, MAP is 90%, injectors are wide open for this situation, but AFR is topped up at full lean for 1 full second, then everything's back to normal... 1.1° of knock retard. Any idea? If you need a log, I'll be able to upload it tomorrow when I wake up.

[TiCPU]

Here is the graph, don't mind the knock, I just installed the new pulley and need to tune that out, also still playing with AFR tuning.

[Japeatr]

Dcfo?

[TiCPU]

I will try a run with it completely disabled. Let's see!
Correction: The log bits I logged have DFCO, it appears as Off all the way, could it still be DFCO?

[TiCPU]

I just got the worst lean spike ever (on my car), this was a complete second of lean'age and really bad jerking.
Lucky I was logging data while cruising around, thanks to the pro version of the interface.
This time I did not even have to shift, I just stomped on the gas and I was projected to the steering wheel at least thrice. This time, I've got the log file: 20100530-1-Beauceville.hpl
Look from frame 23463 to 23475, I released the gas because I though it was just dead afterwards, then after depressing the pedal again it was fine...
That is over 1 second (19.260-20.390), I don't know why injectors would stop firing for this long, makes no sense.

After reading posts in the forum, it seems having the config file is useful, here:
WB.cfg

[CarsonTech]

Would you be able to post your tune that this happening with and that the log file correlates to?

[Frost]

It's crazy wideband latency/lag for one thing. That data is way behind. I don't know if it's in that calibration, but it looks like CFCO. Clutch Fuel Cutoff.

[TiCPU]

Would you be able to post your tune that this happening with and that the log file correlates to?

Here's the file!
COBALT2.0LSJ-OEM-Stage3-20100527-2.9.hpt

It's crazy wideband latency/lag for one thing. That data is way behind.

I noticed that already, it's weird, the sensor is brand new, is placed just before the cat, about 50 cm after the NBO2, makes no sense that it is sometime 50 to 100ms behind the NBO2.
Anything I could do?

I don't know if it's in that calibration, but it looks like CFCO. Clutch Fuel Cutoff.

That would almost make sense, but I never seen it in my HPT file :-/
I changed clutch though, and it doesn't grip at the same spot as the old one.

[roderick]

I looked at both your tune and log file and noticed two things right off the bat. The first is your pe enrichment rate its set at 1.000 you should really set it at 1.500 so it enriches faster. Also another thing through the whole log you did your air fuel is every where. You need to tune your maf alot. There was spots where your air fuel at crusing was 11.8 and other areas where it was 18.6 you need to do alot of maf tuning. Once you tune your maf everything should be just fine then. Your wot maf looks off by 2-5 in some areas you need to get it to -1 in all areas same with your crusing get it to + or - 1 or 2. Once you do that you should be gold. Another thing to is your high and low octane levels. your low octane is way to low. You need to take your high octane and paste it into your low octane and then subtract 4 from it cause right now you have it set to 4 and your high octane is set to 16. So if you are going wot and you get knock and your car goes to the low octane table it will command 4 degrees of timing and that is way to low. You cant just go from 16 to 4.

[TiCPU]

I looked at both your tune and log file and noticed two things right off the bat. The first is your pe enrichment rate its set at 1.000 you should really set it at 1.500 so it enriches faster.

Immagine that GM had it set at 0.200 Injectors are wide open though, but could make sense.

Also another thing through the whole log you did your air fuel is every where. You need to tune your maf alot. There was spots where your air fuel at crusing was 11.8 and other areas where it was 18.6 you need to do alot of maf tuning. Once you tune your maf everything should be just fine then.

I'm currently tuning the VE table, next is the MAF table, I'll get back to this thread once everything is fine-tuned then!

Your wot maf looks off by 2-5 in some areas you need to get it to -1 in all areas same with your crusing get it to + or - 1 or 2. Once you do that you should be gold.

Those numbers are % or AFRs?

Another thing to is your high and low octane levels. your low octane is way to low. You need to take your high octane and paste it into your low octane and then subtract 4 from it cause right now you have it set to 4 and your high octane is set to 16. So if you are going wot and you get knock and your car goes to the low octane table it will command 4 degrees of timing and that is way to low. You cant just go from 16 to 4.

That makes sense, this was a canned tune from ZZPerformance, I'll do that!

Thanks for your tips!

[TiCPU]

Forgive me for all wasting your time!

... but it looks like CFCO. Clutch Fuel Cutoff.

You were completely right.

Even though I searched for such a parameter and didn't find it, I didn't even try to just depress the clutch and hold the throttle, it stopped at 3k, then after thinking again, I did set the P/N Cut off to 2800 to make sure no one abuse the car while it was cold or just because it was nice to hear the supercharger at full throttle.
So when shifting, cut off at 2800, jerking, and now it makes sense, even if injector were still wide open?

Thanks for searching, now I will be able to complete my tune!

[roderick]

The 2-5 was % by the way and yeah if you have zzp caned tune thats why. I had a buddy with a tune from zzp and I redid it and he made another 15hp. So I would just go through it and get everything right and you should be golden. I would also tune the maf before the ve since our cars use the maf and only use the ve when the maf fails or when we step on the gas really fast in like 5th.

[HNRClothing]

The 2-5 was % by the way and yeah if you have zzp caned tune thats why. I had a buddy with a tune from zzp and I redid it and he made another 15hp. So I would just go through it and get everything right and you should be golden. I would also tune the maf before the ve since our cars use the maf and only use the ve when the maf fails or when we step on the gas really fast in like 5th.

I thought the car is set to use VE up to 3400 or 3500 and MAS beyond that. I have seen a lot of canned tunes that only use MAS, I have not seen his tune so I am not sure what his is set to.

[laser_racer]

There is a bunch of stuff in there that needs to be turned off. Also if you do not make the maf fail its still going use a blend of maf and mas from what I am told. Also your injector tables look really crazy and not smooth. The maf isn't very smooth could be better and the ve table is really really rough. I just wouldn't think it would be there crazy looking. That is just me though.

[Frost]

Forgive me for all wasting your time!


You were completely right.

Even though I searched for such a parameter and didn't find it, I didn't even try to just depress the clutch and hold the throttle, it stopped at 3k, then after thinking again, I did set the P/N Cut off to 2800 to make sure no one abuse the car while it was cold or just because it was nice to hear the supercharger at full throttle.
So when shifting, cut off at 2800, jerking, and now it makes sense, even if injector were still wide open?

Thanks for searching, now I will be able to complete my tune!

Send it to support and ask them to add it to the definition or maybe just ask them if they can disable it in your file. I don't know that they can, but it's worth a shot.

[csementuh]

I also go really lean when I shift and the clutch is in. Is there a setting or fix for this? Mine is a LSJ in a Cobalt SS/SC.

It also seems that DFCO sometimes will kick in even though all of the temps should have it disabled in the tune.

[roderick]

I thought the car is set to use VE up to 3400 or 3500 and MAS beyond that. I have seen a lot of canned tunes that only use MAS, I have not seen his tune so I am not sure what his is set to.

lol yes I forgot about that. I am on 100% maf and I love it. screw the ve I go 100% maf if I was you tune that then work on your ve.