I have had this issue posted on HPT, but you guys seem to be more responsive on here.
My TBSS was professionally dyno tuned WOT, but I was stuck with cleaning up the rest of the tune. I had it almost done, when one day it started violently sputtering in boost. It runs great in 1st and 2nd gear. It may be that actual gear is irrelevant, but rather the greater "load".

The scan shows that bank 1 O2 goes from good (+900mv) to completely lean (20mv), really fast (no KR though). It's like it is switching in and out of DOD (displ. on demand), but I've made sure it's deactivated, not to mention it should never come on during heavy throttle.
The scan also shows the injector pulsewidth of bank 1 rising quite a bit higher than bank 2 during the sputtering.
Also the timing will step its way down close to 0 a few times during the pull, and then immediately jump back up to where it should be, but it's not retard, and I do not see anything in my tune that would cause that.

FYI when this issue started I upgraded to 2bar OS so it would be easier to work with.

Here is one of the scans. Look at the end, near frame 12,500.

Any help would be much appreciated

 

What's the tps doing?

I rember a local turbo tbss had alot of issues with the throttle moving under boost and it making the ECM do weird ****

 

The throttle is working properly, but it's funny you say that, because when I first started logging this thing I thought I had an issue with that function. TPS only reads between something like 22-82%, but then I learned that they all do that and you have use the ETC% PID when scanning.

 

Finally I'm getting some clues!!! Since I've been getting nowhere, I decided to go back to my 1bar map and tune, even though that's how it was setup when this whole problem started.
But NOW, it doesn't sputter!!!!! I wish I could say "problem solved" and move on, but it's never that simple is it?
It's like there is something wrong with my ECU or OS. I didn't bother to mention at the beginning this the post, three strange things that happened when I enhanced to the 2bar.
1. A few months ago it began to not shut off when I would turn the key off. I could turn it off, remove the key, and it would just keep running. I tried everything I could to fix this problem, without success... until I converted to 2 bar, it magically fixed itself!
2. The tranny used to shift VERY hard no matter what I did to any of the shift tables... until I converted to 2 bar, it magically fixed itself! Even though all the trans. tables were the exact same.
3. The AFR is terrible now, across the board (too rich here, too lean there). I know it looked better than this before. And I really don't know what I'm doing with that confusing 30 section chart for VE.

Now that I did a Write Entire back to 1bar, I have these 3 problems, but on my 2bar OS I have the sputtering dilemma.

Does anybody know what is going on? I feel like I am in the "Twilight Zone meets Burmuda Triangle" realm!!! lol

 

Anyone?

 

Get it tuned by a professional !

 

I spent $650 for a "professional" to "tune" it. When I dropped it off he said to give him a few days, which turned into 4 weeks because he didn't have time to get to it. Finally he told me it was ready to pick up, so I took off work early to pick it up. And when I get there he is like "oh by the way, I only tuned WOT. Just call me one weekend and we'll finish the tune on the road" . After 2 months and many "postponed" attempts to meet up, he finally "almost" finished the tune, then we ran out of time. And again he said we would finish it another day. I was tired of that game, so I bought HPT.

FYI I am not going to say who he is, because he does good work when he gets around to it, and he is a nice guy. He just has more business than he has time for. He is a VERY heavy hitter in drag racing as well.

 

A good tuner wont charge you $650 and keep bullshitting you time after time! or leaving you with a car running like ****! Your a customer and you payed for his time! id get my money back!

 

QFT...

that **** would **** me off

 

I did try to get a little money back the last time that he almost had the tune finished. But I didn't get anything.

As far as I'm concerned it's water under the bridge now. The whole sputtering thing was not occurring when he tuned it. So I don't really consider him to be responsible for the sputtering.

 

what does that mean?

 

I would confirm you actually have a 2 bar MAP sensor and also make sure the MAP scalar and offset values are correct in the file.

 

Thanks for the advice. The sensor is indeed a 2 bar, and from what I can gather the offset is right. As for the scalar, are you referring to how the KPA values across the top of the table VE table can be altered?

P.S. You have good taste in vehicles! lol

 

No TBSS or Ram Air TA envy there, LOL

 

Thanks. I actually sold the TA last year and bought a ZL1 but never updated my sig.

The 07 TB SS uses the E67 ECM which has the Virtual VE Tables for OL/CL and 1 bar, 2 bar and 3 bar. I don't know if HPT COS gives access to the VVE tables; but I wonder if this a MAF only tune? There are two MAP values in the tune you need to change when switching to a 2 bar; MAP Sensor Scaler and MAP Sensor offset. I'm sure the previous tuner changed it; but it doesn't hurt to make sure. A quick test is put the Key On/Engine Off and check the MAP kPa reading because that is how the ECM establishes baro. Sea Level is 101 kPa; so depending on the weather and elevation it should be in the high 90's.

P.s. -The factory installed LS2 in the TB SS is not an DOD or AFM motor; so that is not the issue.

 

I see the MAP offset under diagnostics>airflow, which is at 10.34. But I can't find any MAP scalar.

I think the MAP stuff is correct though because it usually reads 100KPA when not running and when I scan in boost it matches right up with my autometer gauge.

ZL1=NICE!

 

I thought I found the problem today as I was browsing through my tune. Under Engine>Torque management>Supercharger, there is a torque limiting parameter per gear, and it was set at 3rd-5th, and I got all excited and disabled it, but it still does the sputtering.

At the top of the supercharger section, it was already selected as "not fitted" with a supercharger, so I guess that may have already disabled the whole entire function anyways.

 

I'm not a tuning expert by any means, but here are some things that come to mind...

Are all the mechanicals working properly?
Fuel pump?
Fuel pressure adequate?
Duty cycle on injectors not maxed out?
Is the pedal communicating with the tb correctly? (I seem to recall some people having problems with the TAC module on the fly by wire vehicles).
Transmission in good shape? Not slipping or the TCC acting up?
How do the coolant temp readings look? The computer reverts to -30 when it fails or becomes unplugged. Are the connections good? Wires good?

Again, I'm not a tuning expert but I know these things would contribute to the issues you are having?

 

Yep, everything you mentioned, I have checked/ruled-out as not being the problem. The strange thing is that it doesn't act up in 1st or 2nd gear.

I appreciate you taking the time to help think through the possible causes.

 

Sometimes it's not always in the tune. I'd revert back to the 2bar os.

How much boost are you getting in 1st/2nd and how much in 3rd? Most likely you're seeing less boost in 1st/2nd because like you said, less load. Violently sputtering seems like a spark blowout issue to me. And its showing lean because the fuel isn't being burned seems to prove that. What plugs are you running and what are they gapped at? I would try gapping them tighter. Your idle will be less steady but you gotta pay to play sometimes. I'd start at the plugs first.