whats this called
 

Not sure what its called?
But the screw is missing where can i get a new one or how do i fix it?:scratch::scratch::icon_tdow

A clearer pic would be helpful. Also, what model rx7?

It is the Bypass Air Control valve also know as the "BAC."

what "screw" is missing?

If the component is for a turbo then there should be an adjustment screw in the tube sticking outwards from the engine. If it's for a non turbo then there is no adjustment screw.

Are you trying to say this screw is missing?

http://lh6.ggpht.com/_nrSHAwzrLVs/TM...m_blog_bac.jpg

yes sir thats it and its a 87 turbo 2 s4 with s5 manifold and that screw is gone.

I looked in the hole looks like it was broken in there....
i think it might be the last part to why my car idles a little funny.

Where can I get one for a turbo or is there a way to fix it?

If the screw is missing, then putting your finger over the hole while the engine is running will allow you to feel vacuum. If there is no vacuum present, then don't worry about it.

Okay I'll try that, the thing is tho I timed it fixed the tps, throttle cable
and when I first start it up it idles great but after a min it starts to jump up and down

I have a clogged catylac converter and some of the hoses are a little old
other than that everything is in working order so I'm not sure I thought it would be the bac
since missing the screw...

Thank you for the help anything else is awesome.

The car needs to be thoroughly warmed up before the TPS is to be adjusted in case you did not know that.

Yea it was done at a shop and they are the ones who said it was the bac due to the screw being missing or stripped and broken.

Put my hand over it and nothing what could be the cause of a wierd jumps then
it idles okay for a min then ifi push the gas a little it jumps upand down.

from 750ish to 1300

Test and adjust your TPS. Check for vacuum leaks.

Where would i start looking for a vac leak if its not the tps, would it be a boost or a leak somewhere else?

also to make it a little clearer sorry i was on my ipod when i posted last.

It idles around 750ish then when i push the gas to rev up or just to go when i let go it starts to do the jump but when im on the gas actually moving it runs great its just when i let go.

Also was wondering if since the screw is stripped in the BAC or missing should i just take this opportunity to get a new intake manifiold?

If so is there a kit with a BAC and intake manifold?