Agreed with the pump theory - maybe I'm cranking too soon? Either way, goes like stink at full throttle so must be ok.
RE the intake - I just find the concept of bonded intake pipework ridiculous. It clearly doesn't last as it seems most people's mafs eventually break away from the elbow and it even has a flanged inlet face with four bolt holes as though it should correspond to a flange on the pre-maf pipework. I've never owned another car with bonded pipework, its always sleeved/clamped.
I can't even see why it was moved for the ZT. It sits up top in a mustang, and gains almost nothing by being where It is on a ZT... Apart from potentially being out of engine bay heat soak?
Herman, does yours sound throatier with an open filter? We hired a mustang GT-H in the states and albeit a slightly different engine, the open filter in the engine bay have a serious growl when pushed!!