Hi guys just needing some advice on how to diagnose the actual problem of low boost on the 2nd turbo.

Here are 2 short clips that show how low the 2nd turbo sits only at about 5 psi and runs rough


Any ideas on what to inspect first would be greatly appreciated :-)

 

If it's not clear the first vid shows the 1st turbo boosts at about 10 psi , but when the second turbo kicks in it drops dramatically - down to about 3 or 4 psi.

 

It can be many things, when did the issue start?

 

It's a new import (only had it a couple months) so has probably been doing it the whole time. I always noticed the 2nd turbo didn't feel as powerful but it was only until I watched the boost gauge that I actually saw the massive drop in boost. I've recently checked all the vacuum lines and replaced about 50% so I'm sure I can rule out vacuum lines below the manifold at least.