Secondary Port Throttle Actuator vacuum leak

[boostedmaxPSI]

Guys,

Something had been gnawing on me about the condition of the secondaries and how well they were working. I had addressed the vacuum leaks but I always felt something was fully opening/working.

So.... off comes the plenum again, for additional testing for peace of mind.

This time I hooked up a vacuum gage inline so I could see how much vacuum was being lost when I backprobed pin C17 to activate the secondaries.

First thing I noticed was the driver side secondary ports were fully open and the passenger side ports were only opening part way. In addition to the passenger ports not opening all the way, my vacuum gauge would drop below 5" and the driver side actuator would start to close partly.

I isolated the problem to the passenger actuator itself. Please see the attached video:

http://www.youtube.com/watch?v=yjtZA...ature=youtu.be

Notice how the vacuum starts to bleed off almost instantly. This does not happen to the driver side actuator however, the passenger side actuator will hold vacuum when you go above 15" vacuum. I assume this is because the internal diaphragm is laying over itself and sealing the internal leak.

Another observation is how the diaphragm pulls in at an odd angle. Seems like something is not centered internally to the actuator.

Thoughts?

I plan on purchasing two new GM units tomorrow. Who do you recommend that I source these parts from?

thanks
Frank