Hi mrockm, Looks like an older thread but is similar to what is happening to my BA XR6T. If I just give it a moderate hit, the boost is fine, if I dump it, it will get to probably 4000ish then shudder. When I pull up, the car shudders as if running a couple of cylinders short. If I give the pedal a hit again the car comes back to normal once the turbo spools up a bit then idles fine. I had new Weapon X coils installed just over a year ago so not sure if it would be those. I've seen on some other threads about lubing the boost control solenoid as it can get gummed up. Other things mentioned - vacuum, fuel filter, fuel pump?? Any ideas or experiences would be appreciated. Thanks.
