car's weird

[99 gst spyder]

Ok, heres what i have to ask you dsmer, my car stutters alot when i hit full boost at 18 psi and will sometimes go past 18 psi(no boost controller), and i'm wondering what's causing it to do that, it's done worser than that to, then i previosly change all my spark plugs, ran a little better but still have the stutter at 18 psi. when i swap my 16g in, the j-pipe didn't have any hole where i can tapp the line from the waste gate to, so i took that line and T it with the bov line running from the intake manifold. then when wot at 18 psi, cars starts to stutter alot and when i release the gas pedals, my bov sounded like it shoudn't be, very low sound.
so is it that line i T it with the bov or do you think it could be the watse gate in some sort? any help?

 

[GofaST4life]

im not sure why it stutters, do a boost leak test just to rule things out...but i do know that you shouldnt T into the BOV line, its best to leave that as it is...

 

[Talonracn50]

18psi from a 16g on a stock fuel system is suicide for your motor. I didnt see any fuel mods in your profile -- the bucking is from the engine running lean or hitting fuel cut or both.

 

[wishnfor4g63T]

I wouldn't tap the bov line period! Out of curiousity i tapped mine on a 16g install and here's what happened. First the blow off on my greddy type rs was not right. When you let off the gas it hit the vacume and didn't blow off. The other was the car never boosted past 12 psi.

Take your J pipe to a welder and have it tap'd with a barb. If you don't wanna go that route then get your turbo tap'd on the outlet like the t-25. Either way it's gonna work.

I agree about the boost you shouldn't be hitting 18 pounds even with a a/f gauge. Wait it out and get injectors and a fuel pump and some sort of logger or afc. It might suck boosting at 13 pounds but hey your car will thank you by living alot longer.

I just replaced spark plugs on mine was having the same problem. Not so high in the boost but it started on my t-25 turbo and had it replaced. Thought that would fix the problem being huge shaft play but nope still there. Bought new spark plugs "NGK BPR6ES" gapped at .028 (if you don't have these then go buy them). Car ran smooth and no hesitation on the top end.

Good luck with the car man!