I found that it leaked to much air via the hose coming out of the cam cover.
So when I was doing it from the intake pipe it would just leak.
Doing it direct from the turbo cuts out that.
Also I found my engine just wouldnt build or hold the compression when I had it going into the manifold etc.
This is why I just gave up and took it for a smoke test, which in the end didn't tell me anything really