Stutter at Higher RPM's

[BoostActionBob]

I have a 1991 TSi mods are in my profile. i have been experiencing a stutter like feeling at higher rpm. anywhere from 4500 to 6000. i have adjusted the fuel settings to lean it out a bit and it fixes it for the time being but it comes back even with the fuel settings adjusted. my logger took a dump on me and am awaiting a new connection cord for it. i was thinking it may have been a boost leak that was affecting it under higher rpms. so i ordered some silicone couplers. one for my turbo to intake and 2 for my gm maf. any help is appreciated.

 

[95blackGsTurbo]

Plugs that are off on their gap will do this. I battled when I first got my 2g DSM way back in the day. If the gap is too big it in the higher rpm's it won't be able to make the jump once and a while and will start to miss. You REALLY need to leave the fuel turned up without a datalogger. You could be leaning the car out to much causing a lot of knock.

 

[BoostActionBob]

i have the car running fairly rich as of now. i am running the ngk bpr7es spark plugs changed about 30 miles ago gapped at .028