Boost pressure trouble

Good day!

I have changed my turbocharger for a new unit but the problem is it gives only 0.4 bar, regardless of rotations or load. I have tried increasing preload on the wastegate spring, installing a ball type boost controller, but nothing helps, it won't boost more that 0.4 bar. Besides, the boost gauge needle vibrates wildly, a thing that never happened with the old turbocharger.
What could the problem be, and where should I look? Maybe I'm forgetting something.

Please help!

Let's block ads! (Why?)

Boost pressure trouble