I have an 09 ss tc. Catless downpipe, bigger intercooler, intercooler piping, air intake, exhaust, trifecta tune. 30k miles. Car runs and drives fine under normal conditions. Occasionally though im having a problem, at WOT first gear to second...Car will build boost to about 23psi then i shift and it sound like the car is on the rev limiter (missing and popping noise) and if i stay to the floor it will continue even in second gear and no where near redline! If i let off completely for a few seconds and then drive normal no issues. The car seems to be holding boost while this happens. Sometimes i have no issues though. Today it did it again, I shifted first to second around 5500 (so under the rev limiter) and it continued to miss and sputter after i let off and drove normal for about 30 seconds then was fine. Im not getting any lights when this happens either. Any ideas or places to start looking??

 

Sounds almost like the misfire you get when you NLS when the engine is still cold. Have you asked Vince? Maybe try to catch it during a log?

 

I'm gonna guess misfire. Check your plugs.

 

Mine would do that with a pretty bad boost leak. 3/4in cut in my silicone coupler on the hotside charge pipe going to the intercooler.

 

Well, im gonna check with vince, check the plugs, and see if I can find any leaks.

 

if youre on original plugs still since day 1 swap them and i would even say go to the 3787s. Some LNFs like them some dont though. Mine is very happy with them

 

replaced plugs, still having the same issue. Any other suggestions?

 

Do you build boost with rev of the engine in neutral?

 

Never tried in neutral. Should I?

 

No, you shouldn't. If you are, you might have a TMAP issue.

 

Are you NLS'ing to late?

 

I actually am not NLS'ing. This usually occurs somewhere over 5500rpm. There have been times it doesnt though. It sounds like when you hit the rev limiter except it stays after the rpm drop. One time it actually shut the car down. I was able to restart without issue.

 

I have had the same problem for a while... When you figure it out let me know also.

 

i think i no what your talking about when i was at the track i launched rode out 1st a little went to second and it sounded like my car was misfiring really bad and had a loss of power but then it picked up after awhile. No idea what causes it but were attempting to figure it out with a log on HP

 

You are describing it perfect! If you find out please let me know. My next step may have to be data log, which im not currently set up to do.

 

kinda have the similar issue... its only sometimes so i kinda figured i was NLSing too late.. in for results

 

.. well its either of these. Map/ maf sensor. Boost leak which is very common. Coils or Injectors. Or tune .......if u send a log to vince he should see the issue.also if Ure purge is bad it'll Skew trims enough to cause it to do this.

 

What would be a good way to check for boost leak?

 

I've tried to get it to do it while logging but vant get it to. Its a pita problem to recreate

 

Shifting too quickly causes it for me as well.. shift a little slower and it won't happen; that's been my experience so far anyways. I'm not sure, but I think it's cause there's a higher amount of boost at high rpms over stock causing this issue. Vince told me it was either lower boost at high rpm, or NLS.. I, as most others would agree, chose to keep the boost

 

^: wtf.................. Lower boost at higher tons has nothing to do with anything. Maf calibrations changes with hertz not rpms. Unless the load is different and ect.

 

Higher "tons?" wtf?

 

My car actually did this when shifting 2nd to 3rd. When i got retuned it fixed that completly havent done it again.

 

Lmfao sorry... My phone spell checked it I guess. Rpms lol

 

Mine does it from 2nd to 3rd and it bugs the hell out of me. I noticed it more when its cold, but I let my car warm up for a few minuts before I even drive it should be plenty of time. It is getting colder now but I shouldnt have to worry about my car not wanting to go when I'm getting on the highway.