Topic: Bog after shift - need input

[jae]

I am working with Trifecta on a custom tune for my Sky RL.  I have the FP68HTA turbo kit from Dejon installed and am up to 22 psi on 91 octane so far.  Everything is OK, except that I am running into a bog, up to a second long, when driving hard (near redline shifts).  The bog happens in the 1-2 upshift and starts after I am done with the shift and fully depressing the go pedal.  Then the turbo spools back up and off I go.  At the same time, the CEL blinks and I get P0300, P0302, and P0303 which I think are misfire codes.  I tried a no-lift-shift to see if the bog was wastegate/spoolup related but this only made the bog worse.  Trifecta is dedicated to working on this but has not figured it out yet.  Anyone have a clue what might be causing this?

[2kwk4u]

It's a common issue with GMPP-tuned cars (mine included).  I rarely get a CEL.  P0300 is a general misfire code, and P0301 - P0304 are misfires in cylinders 1-4, accordingly.  I've only gotten a CEL from mine once or twice.  When I monitored with a borrowed Dashhawk, my misfiring cylinder was inconsistent (sometimes cyl2, sometimes cyl3) and usually didn't meet the threshhold to set a CEL.  

It seems like some have had varying success swapping in hotter plugs to rectify these issues.  When I get sick of it again, I'll give NGK 3787's a shot.  Please keep us posted on your findings.  

Oh, and welcome to Kappa Performnace!   

[DeepBlueGXP]

Do you have upgraded hose clamps?  Blow by will cause your car to bog down and throw those codes.


Acdelco 41-108 are the hotter plugs.  I think after May 07, they were used in all 2.0L.  I pulled mine and I had 41-102, Feb 07 build date.  My son's car was built in May 07 and had the 41-108s.

[NormSky]

You bean colder range plugs?


Norm

[NormSky]

I see!


http://www.skyroadster.com/forums/f5/old-spark-plug-question-29039/

http://www.solsticeforum.com/forum/f43/spark-plug-help-47110/


Norm

[DeepBlueGXP]

Yup

FWIW The original gm bulletin about this change said, "The replacement higher heat range spark plugs have better cold start characteristics."

[jae]

I think it might be the BPV solenoid not dealing with the high boost and new turbo very well.  I am going to bypass the solenoid tomorrow and let the BOV see pressure directly from intake manifold.  My hope is that the pressure from the manifold will hold the BOV closed after I shift.  The kit I have has a build-in boost leak to prevent compressor surge.  I sometimes wonder if this bleeding too much pressure off.  The hose used is about 1/2" ID.  If I still have this issue, I may try to restrict this leak some but I don't want to deal with surge so it may be a balancing act.

[shabby]

The kit I have has a build-in boost leak to prevent compressor surge.

This is the first thing i would throw out if had that turbo setup. Your making a boost leak to prevent compressor surge? You're going about it the wrong way, simply make the turbo spool up slower at low rpm through the boost control solenoid.

[jae]

Shabby, the kit came with the built in boost leak.  The leak was to prevent compressor surge, but I plan on blocking the leak (and checking for other leaks) this weekend so hopefully this will fix the problem.