Boost issues on my fiat coupe 20VT. Can anyone advise?

[swiftpete]

Hi, I have been having some issues with my car overboosting. I have a blitz dual sbc and usually boost to about 1.2 bar. The other week the car overboosted and it turned out the pipe that connects the boost solenoid to the wastegate actuator had become detached. So it was reattached. It's since come off again twice. The last time I clamped it on tight. So this makes me think there must be something wrong somewhere that's forcing it off. I decided to bypass the boost solenoid to see if the wastegate was sticking shut. Joined the 2 pipes that normally go into the bottom of the solenoid, took it out and the max boost I got was 0.58, with it holding about 0.5ish.

Although I'm not an expert, I think that means that the wastegate can't be sticking shut otherwise surely it would've overboosted even without the solenoid connected wouldn't it? Does this mean that my boost solenoid has shot it? Anyone with any ideas? This is the first car I've had with an electronic boost controller and I've just looked at the price of replacements. I hope it's not that as they're not cheap!
I'm no expert although trying to learn, so any advice would be appreciated!
Cheers,
Pete

[scotal]

Nothing practical to add, but i think the guys on the FCCUK forum wouldknow what your problem is. Might be worth giving them a try.