whats this?
 

Took off the carb and I dont know what this plate is that is built into the rotor housing also am I missing something that hooks it to the solonoid?
http://home.comcast.net/~ginman999/rx7question.jpg

RE: whats this?
 

It is called a 'shutter' valve and should be attached to the vacuum diaphram to the left with a short link. The system is designed to close during decel and shut off the primary side of the carb to help in backfire prevention on decel. With it closed the way it is, you probably have a power loss problem. A new shutter valve (the vacuum part) will come with a new link but if the peg attached to the butterfly is damaged you will have to replace the intake manifold as it is not a separate part. Ruptured shutter valve diaphram is very common on older 12A carburetor engines and if left unrepaired the vibration caused will exactly what you have found.

RE: whats this?
 

How can I tell if the manifold part is bad before I buy the sutter valve?

RE: whats this?
 

Make sure that the shaft and butterfly move freely from fully open to fully closed. Then check that peg that is circled. It should be equal thickness along entire length and on the end should be a groove that would be used to install a small snap ring. Drew a rough picture of what that little peg should look like.

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