Boost Problems

[TwoHarbors240]

I have an RB25 in my 240 that I recently finished but im having some boost issues. It has a 1.0 bar spring in it so it should boost to around 14.5 psi. Its not, it boost to well over that, easily. I took the wastegate apart and noticed the diaphram was bad and pinched so I replaced that, replaced all the vacuum lines, including the line from the wastegate to the turbo, and also re-did the line from the manifold to the boost gauge. Does anyone know what could be causing it to boost so high? thanks

[s14unimog]

I'm assuming this is an external gate? If so, how is its dump routed.

[cotbu]

Take pictures of your wastegate setup, I've seen vacuum lines routed wrong on TIAL gates cause this. I could only assume what's his face is thinking, a back pressure issue!

[s14unimog]

ya think? :cj:

[TwoHarbors240]

Yes its an external Tial 38mm wastegate. It has a rubber line that runs from the fitting on the bottom of the turbo to the fitting on the SIDE of the wastegate, not the top.

[TwoHarbors240]

Still having issues.. Anybody had this problem or know what it could be?

[TwoHarbors240]

What should vacuum be at during idle, and when youre cruising??