Asking for a buddy of mine. We're trying to figure out what's up with his car. It's been a project car for him for a couple years now. It's on a smallish turbo but it's heavily modified aside from that. Engine is built, headwork, cammed, Wolf ECU, etc etc. He got it running a few weeks ago but has been taking it easy during engine break-in for a couple hundred miles. It ran a little lean under bost but not too bad. He took it in for a paint job a couple days ago and when he picked it up it ran like shit. It idles fine and builds revs like normal but as soon as there is 0 vacuum to maybe a pound or two of boost, it falls on it's face. It feels like it's hitting fuel cut. He drove it up there and it ran fine, they put less than a mile on the car while it was there and the ECU hasn't been tampered with. We ran a compression check and that checked out fine, no leak down, nothing. Everything seems normal. My only thought right now is the plugs or coil pack. Any other ideas?

 

sounds like a pinhole in the IC piping?

 

Did you do a boost leak test? Make sure the MAS is plugged in? My guess is you have a nice size boost leak somewhere. Also check and make sure that the wastegate did not come disconnected(I assume your running the stock internal).