Hello I'm hoping someone in here might be able to help me figure this problem out. I've got a LHU running on a LNF 2010 cobalt ecm. Engine is all stock other than a 6758 turbo from zzp. 25 lbs of boost on E50 and 20 degrees of timing. I've been running it almost 2 years now on my airboat. And Recently My turbo broke at the shaft the exhaust wheel was laying in the exhaust housing. So I ordered another 6758 turbo and for a month now I've been fighting with the new turbo. It comes up on boost great. But when I lift the turbo is fluttering. Or shuddering. I've changed the bov valve out and put the one from my old turbo in with no change. I've changed the solenoid. And the plastic Vacuum canister. No changes. So last weekend I hooked the bov straight to the intake manifold . Bypassing the solenoid and canister. It seemed better didn't noticed the shudder as much till later that day I ran the boat through some thick woods putting more of a load on it and the shudder was still just as bad. It's Stalling the compressor so much when I get in and out of the throttle I can feel it loosing power. Not good at all. I'm outta ideas if anyone has any please let me know I've got to get this thing figured out before I hurt this new turbo. Thanks John.