Have you ever heard of a problem with tuning, where the car runs well below about 50% throttle and anything more it sputters and no power. Feels like some turned the ignition back to 10 degrees after TDC. Or like the fuel is lacking. The car doesn't stop, it keeps accelerating but very slowly, sputtering the whole time. When it happens (pedal to floor), the wideband O2 reads 10.5, the timing drops to 12 BTDC and boost is normal. Though the problem kicks in at around 3000 rpm and 10 psi of boost. It varies, but is around there.

New plugs, new fuel filter, new UTEC. Problem started all of a sudden, not gradually. Ran OBD II, nothing.

Running 20 PSI boost, mapped fuel to 10.5 after 60%throttle, etc.
Have VF22 turbo, MRT fmi, Perrin fuel rails, PEI 650 injectors, uppipe, downpipe, 3" exhaust, UTEC, BOV, grounding kit, Perrin turbo inlet hose, Walbro FP, Perrin pulley.

Help!!! Spent two months struggling with this one.

 

it misses badly from 3000 rpm to redline.

 

Thanks. I am going to try a coil pack in cyl 1 and 3. I heard of another owner who had the same problem and this fixed it.

 

thanks for the info. I can't disconnect the utec, the stock ecu won't fire the pei 650 injectors. the utec detects only knocking if I disable the cel in the perameters settings. If I don't disable the cel, it will flash whenever it detects something. I do have a scanner and just ran it, shows a P457, emmisions leak. I am going to replace the gaskets in the intake manifold and also the TGV to the head. I am not getting a misfire on the scanner anymore, had one last summer before the problem started, replaced the plugs. Maybe one of the tumblers is stuck closed? I'll keep plugging away at this very mysterious problem. If anything else comes to mind, let me know. Thanks