GN is surging under boost.

[SS_Sean]

Hey, guys, been chasing one thing after another. The other night while out trying to get the tv cable adjusted I did a WOT pass to get to max boost. The car went up to the usual 15psi and sputtered, and started bucking and surging. I backed out of it immediately. I went part way into the throttle again, and attempted to build some boost and it just surges and sputters now as soon as I go from vacuum to boost. At this point the car runs great if I'm in vacuum, but does the surging and sputtering ever time I try to boost it up. I parked the car and noticed the scan master in recall mode said 940 and 3.2. I was not able to get to WOT today, but it read 940, so I'm not sure that has any relivance. I realize I should see 780 for proper AF mixture, but that's at WOT. I checked all my vacuum lines and my intercooler/compressor hoses, all looks good. I'm at a real loss here. Whatever happened happened suddenly, because yesterday afternoon this car was running great!

 

[XLR8]

I would first check the intercooler hoses.

I recently had a problem in that the car ran great at part throttle up to about 12# of boost. If I floored it, the car would surge, stumble, etc. It turned out that I was way to rich and flooding the motor - your O2's of 940 indicate you may be flooding the motor. I put in new plugs gapped at .032 and pulled fuel and now the car runs like a champ.

 

[TurboDave]

If the car wont go into boost at all without "acting up" it could be indicative of a couple areas to look into.

Normally it indicates a faulty ignition module, or a faulty MAF. Since you're running a translator with a newer style maf, I'm not so sure it would be bad already, but you just never know.