Need help please

[Adam in CLE]

Hi all! Have an 09 turbo SS that is all stock except a GM stage 1 tune. Issue I am having is over boosting to a peak of 30 lbs of boost. Also, if I lay into the accelerator I get lag then car will go. I have reviewed my tune with the same tune from HP Tuners and see no differences via the HP tuner software. I am thinking there is a vacuum leak but unsure. I could use some help in trying to diagnose and then fix the issue. I have spoken with Adam at DF and we haven't been able to diagnose. Any help would be greatly appreciated. Please ask for any background that is needed to figure this out. Thanks in advance!

 

[Gtstorey]

Send me a log with the channels I sent you.

 

[Gtstorey]

And your current tune if you have made any changes since the last one you sent me.

 

[KSLunsfo]

I would personally start at confirming vacuum line routing / looking for potential vacuum leaks. Also may be worth checking the wastegate flapper/lever on the turbo to make sure there isn't a mechanical issue.

Guess some of this also depends on what work has been done or if this suddenly came about after tuning was done.

 

[Gtstorey]

I sent him a first shot at a tune last fall based upon from what I remember a partial channel list. I don’t know if anything was done after that. What I sent him was far from a finished tune. More like a shot in the dark to get it a little closer.

 

[Adam in CLE]

Tim, the logs haven't changed and based on the tune comparison I don't believe this to be a tuning issue at the current time.

The waste gate does function properly. What is the best way to look for vacuum leaks? Does anyone have diagrams for all vacuum lines?

 

[Gtstorey]

Smoke machine is the best way to look for vacuum leaks. Second is to spray flammable brake cleaner in suspect areas and see if idle increases.

From what I remember the fuel trims were extremely positive. If the car was running correctly to start with you would see that the fuel trims were negative at idle but got better as rpm is increased. This won't work since yours hasn't been right to start with.

If this was just a matter of a vacuum leak and the tune isn't off, the fuel trims should be negative. I still think it needs tuning.

 

[Ross]

There are a handful of videos on making your own smoke machine, to find vacuum leaks.

 

[Gtstorey]

Got my positive and negative trims backwards in post 7. Fuel trims would be positive at idle with a vacuum leak but get better with load/rpm/air flow.