I have heard similar posts, but they didn't provide the answers I was hoping for...

I just recently bought an '06 SS/SC with stage 2. It was used with 1500 miles from a guy that took great care of it.

Now that I have gotten used to the car, I am getting a little harder on it, and noticing more aspects of it. And lately, I have noticed that when I accelerate hard, and use a fair amount of boost, that the acceleration is a bit choppy.

I am pretty ignorant to forced air induction, so perhaps this is normal, but it feels like problems i've had with other cars. The choppyness(good word) feels like when I owned a 3000GT, and the spark plugs were misfiring. Or maybe even dirty fuel injectors. But like I said, it seems to be mainly when i'm using boost. It also is much much more noticable when it is cold. I don't get on it hard till the engine has fully warmed up, but even with light accelerations that use boost, I notice the choppyness.

A friend of mine that has a Talon Tsi that is turbocharged, said it may be a boost leak, because he has a leak on his Talon, but he also said that he doesn't know if supercharges even get boost leaks.

So in the end, what i'm asking is;

Is the choppy acceleration normal, or is it possibly due to:
Boost leak
Dirty injectors
Bad spark plugs
My own paranoia

Thanks for any help!!!!

 

is it stage 2?
if so you may be experiencing something called "boost surge" Myself and quite a few other people experienced this until just recently GM released a reflash fixing this problem.

and i almost cried the day i got it flashed because my car felt SO much better.

edit: nevermind i just read your sig

go to your dealership and tell them you need the reflash that fixes boost surge that came out about 6 weeks ago or so.

you wont regret it.

 

I'm wondering if I got the new flash or not. I got stage 2 put on a couple weeks after it was issued. I noticed when I go WOT it pushes you in your seat and then when I hit 4500 or so you can feel a second surge. Don't know if thats just the time it takes for me to push the pedal down to the floor.

 

call your dealership, they can pull your file and tell you if there are new stage 2 updates since the last time your car was in.

if there are, go get them.

 

So I just talked to a couple dealerships about boost surge, and they had no idea what I was talking about. But they also have limited experience with stage 2.

I made an appointment in a couple days to bring it in for them to take a look.

I explained that there should be updates for my computer, but they still said they wernt sure. But this was also over the phone, so I bet they didnt look to hard into it.

So when I go in for my appointment, what should I tell them?

That I need a "reflash" for my computer?

Thanks for all the help so far, and any more. Greatly appreciated!

 

Went to the dealership on Friday.

They looked for an update like you all suggested, and found only one update, that is for when my check engine light comes on. Well, my light has never come on yet, but he said that it is the closest thing that he could find to a computer update. He updated my car and I was on my way.

But it definately did not fix it, and possibly it is worse.

So next move is....?

I'll take it back to them, but I don't think they will really know what to do, since I had to basically tell them what to look for last time I was in.

If it is my plugs, or exhaust system, will that all be replaced/fixed under warranty? I have the stage 2, but it is GM parts and installed by the dealership.

Thanks again....

 

Hmmm that's weird....so wait, it like hiccups but you still get full boost?

 

are you using 91+ octane?

 

yeah, 93 from BP everytime

 

It doesnt seem to be as dramatic as a hiccup, but more like a stall in acceleration. Typically from 2500rpm to 4000rpm.

On medium-hard accelerations.

 

Boost guage doesnt do anything weird, but I can definately feel steady acceleration, then it levels off, then back to steady again with no pattern or specific time interval between jumps.

It just feels like the fuel injection is at uneven spurts, or like the SC is giving uneven boost(even though gauge does not indicate that).



Sorry for my lack of ability to consolidate 3 posts into 1....

 

Pull the plugs. I bet that is your problem as that is the same issue I had. Pick up a new set of plugs and gap them at .035. That should do the trick. You may also want to check the vacuum hoses under the hood.

 

Sounds like good advice. I heard a couple other people say similar things. Thanks!


Any more suggestions from anyone is welcome!

 

Is acceleration smoother above 4000 rpm?

 

"Choppy Acceleration"

Would not be boost leak.

It would leak constantly.

I think it is a

ECU/Timing
ECU?Fuel Delivery


Do you have the paperwork for the Stage II install. If not get it, it should be installed by GM.

Is it an OEM Stage II?

 

Not to be a jerk but is it possibler you are just breaking and gaining traction?

 

No offense taken, but no, I am not breaking loose. That would be nice if I could break loose in 4th gear at 2700rpm!


Any yeah, after 4000rpm, the acceleration seems to smooth out.



It is a GM stage 2, but I don't have the paperwork since I bought it second hand.(I wish I did, and I asked for it, but he said he didn't know where it is...)

 

You need to know if it's been flashed..

 

try this site, maybe you should take a print out of this to your dealer .


http://tis2web.service.gm.com/tis2web

 

Little update...


Took it back for the second time, and we ruled out a problem with the supercharger, and he said that he doesn't believe it is the plugs either. He said he is pretty sure it is a fuel problem, and that since everything looks mechanically sound, that it is most likely a programming problem. So we're back to square 1.

But we took it for a drive, and he "took a snap shot" of when the acceleration dipped, and he said he was going to send the info to GM and hope they have a solution.

As I said earlier in the post, I got the most recent update for my car(according to him), and that there is no other update that is released that applies to this problem.

The update I got from him was to fix a check engine light error, but I have yet to see the light come on, so I knew it would not fix it. If anyone knows the name/code for the specific reflash that we talked about earlier, that would be great, but I do plan on bringing in the link to the website on the previous post.




Maybe I should just junk the car, and get a Toyota Echo....

 

Hey man what is your car redlining at.it should be* 7000rpm*. I don't think you got the stage II flash because you need the paperwork with the part # so the dealer can phone it in and get a vci # to reflash your computer. if not it doesn't matter what they do with the scan tool it will not know you have stage II.just to confirm you changed the pulley and put the 42#injectors in the car with the stage II belt?

 

So the reflash is done specific to my car?

I don't have the paper work since I bought the car 2nd hand, and the guy said he didn't know where it is...

Is it absolutely essential that I have that paper work? It may be possible for me to contact him and have him look for it.

 

^^ The flash code comes with your kit.. it's different depending on the model of the car.. IE ION cobalt..

 

How do the SS/SCs react when they have a clogged cat????

 

The cat glows red and the engine stumbles on anything above 3K RPMs.