Did you have to pull the actuator rod out in order to get it onto the waste gate lever? It's supposed to be mounted with a fair amount of pre-tension.

If that's all fine, you could try removing the pressure hose from the actuator. BUT BE CAREFUL your car will run unlimited boost now. If it boosts, it is most likely the amal valve thats knackered. If it doesn't boost, it's the turbo.