When i did mine (and it worked afterwards

) I had the cam turned to it's anticlockwise stop, and adjusted the length of the rod to suit. When the turbo blows, it pushes the diaphragm, and rod outwards, turning the cam anticlockwise. If you've taken the cam off, mind that there is a washer that fits under the nut that holds the cam on. Miss that and you have diesel running out over your engine.Don't know where my washer went to, but I think the replacement I used might have been too thick, not sure. It's very easy on mine to tighten the nut too tight and so make the cam too stiff to be turned.
In retrospect I would have taken the opportunity to replace the rubber o-ring that fits at the top of the shaft that the cam fixes to, just within the body of the fuel pump. I imagine mine is pretty old. New rubber o-ring might have helped (and not losing the washer!) As I recall the advice is to do the nut up finger tight, and I think mine had a blob of yellow paint on it to stop it loosening.
By the way, how did you get the diaphragm off the rod? I failed and ended up getting a new LDA...