kad 32 low boost pressure?

[Volvo KAD 32 tfft]

Here we are 6 weeks in to the "summer" and still cant resolve this issue, the boost pressure will not get above 12psi maybe 14psi at 3500rpm,
I have checked for leaks on the pipework from the turbo and on the inlet manifold, i have no exhaust leaks,
I just got the turbo charger back from the turbo engineers, said nothing wrong with it, I fitted a secondary pressure gauge to eliminate gauge fault,
now have to refit the turbo that i didn't need to take off in the first place, what a cussed awkward job to do on the mooring, thoroughly depressing?:disgust:
stumped!

 

[[2068]]

I'd be thinking "air leak", if the clearances on the exhaust side have been checked and it's spinning freely.
But exactly where from?
Manifold .. Loose bolt somewhere?

 

[targa31]

similar issue for me was identified as a sheared bolt on after cooler.

 

[volvopaul]

Have you checked you tacho is actually correct? You need a hand held rev counter to test the actual revs of the engine.

Is the engine down on performance? Could be incorrect pump timing or pump setting fuel ratio.