High rpm sputtering

[96wagonzilla]

I have a 96 GT Twin Turbo, for some reason, around 5000-6000 rpm, the engine sputters. Its only in that area on the tach. Any ideas??? I dont even know where to begin. I know there are a lot of things that could cause the engine to spit and sputter, but why only in the high rpm area? Thanks for any info you could provide.

[Huffer]

Are you in any particular gear?
Does it do it in neutral?
Does it happen when you go WOT or just normal accel?

Sounds to me like it could be a tuning issue, if everything else is smooth.
Could also be a vacuum problem.

[96wagonzilla]

Any gear I am in, it does it, but only if I am basically "flooring it". Normal acceleration is fine.

[Huffer]

Ok, then it's likely to be a vacuum leak or something like that.

When you go WOT you put the ECU into an open loop mode... which means it's not reading off any O2 sensors. So I'm thinking it's got to be a vacuum leak, or the fuel/air tune is off at that point on the map.