2nd WG actuator fitted (last ones spring force was too low). This one almost has the opposite problem of too much spring force, with >15psi of spring only boost generated. I would expect around 12psi with this setup. Note: This was with 0.5turns of preload.

Replacement WG actuator. Runs with vacuum line disconnected. The spring appears to be too strong with this actuator, despite only having .5 turns of preload on the shaft. Boosting too high as a result. This is the opposite issue to what I had on the original actuator which was too softly sprung.

New actuator with 1 turn preload Vacuum line disconnected.