I don't know about your engine but the DCi 80 like mine as the boost limited to about 1.2 times atmospheric, so would expect the wast gate to be fully open at about 17psi but a scanner may show about 32psi as it's manifold absolute pressure.
I may be wrong here but I am under the impression that if we are talking about the same thing, you say actuator I think it;s a wast gate, that the valve should be closed allowing all exhaust gas to go through the turbo, only opening if the turbo boost gets too high, unless you have a variable vane turbo in which case I am even less sure, but as far as I know only the DCi 100's and above have them.
Can I join in?
First I have no technical knowledge whatsoever so I can only report what I see and call things by what I believe to be the right name.
So,we are talking about a pipe that goes into the top of the (and I'm sure it's the correct name) wastegate actuator...when enough air pressure is pushed through the pipe the actuator pushes its rod out which opens a gate...this gate confusingly doesn't divert the gases to waste but the opposite...it diverts them to spin the turbo, and that is what is not happening,there is pressure there but even under load not enough to crack the actuator...I've looked and looked for leaks but can't find anything.
Am I reading the situation correctly ?
Any turbo I have worked on the actuator is operated by vacuum. Trace the pipe you refer to and see where it eventually ends up. On most diesels it evetually reaches the vacuum pump on the end of the camshaft.
Most comments I have read seem to talk of vacuum actuators yet the pipe to this one definitely blows PLUS the actuator it self (and a new one I tried) blow out not suck in.
By the way the car is running a little better now (still not good -still no turbo ) after I disconnected the MAF...is there any downside to doing that?
A large bore hose comes from the intercooler to - for want of a proper word - a big silver block, the actuator pipe attaches to the top of this and directly past this the EGR bolts on the side - I did say at the start I had no technical knowledge !
Is that description any use?