ssei not boosting

[willwren]

The sensor will read vacuum in the manifold when it should, and boost when it should. That is the proper connection point. You have other vacuum line repairs to make as well, and replace the elbow you lost. When it's all done, inspect every vacuum line on the engine carefully for any leaks.

Once warmed up, your boost gauge should settle in at idle near full vacuum. Anything clockwise from there would indicate a vacuum leak. Using the test procedure from the red link in my signature, test the BCS and BCA for proper operation once all the above work is done. My website details this very well, including with a video. Minor differences should be noted, but will apply to the M90 nonetheless.