Generation1

I own an 84 rx7 gsl, and I am in need of a CST valve, AKA. coaster valve, coaster jet. It is a vacuum diaphram connected to the throttle plate in the intake manifold. It may also be considered a deceleration valve. Does any body know about this part or where to find it. I have already searched salvage yards localy with no luck and I guess new ones aren't made any more.

Second question, will I get that part if I get a new intake manifold, carb or throttle plate?

thanks for any help in advance

Rx-7Doctor

iTrader: (13)

place a WTB thread in the classifieds for a used one.

Can get through Mazdatrix also.

Does not come with the manifold

http://mazdatrix.com/c-5.htm

Might be cheaper at Mazdaautoparts.com

Generation1

thanks for the response and help. I didn't see anything called a cst valve. i will give them a call and check the shop manual again.

Rx-7Doctor

iTrader: (13)

It's called a "Shutter" valve

Generation1

well dont I feel dumb...thanks again for the hook up DOC. Hopefully me and the car we'll be up and at the track soon.

mazdaverx713b

iTrader: (91)

you may be referring to the coasting valve. when the shutter valve cuts off the fuel from the rear rotor during decel, the coasting valve opens, allowing fresh air into the rear rotor to prevent excess drag on the engine due to the rear rotor slugging along without and air/fuel mixture. did you test your current coasting and shutter valve?

Generation1

Yeah the coaster valve soesn't function properly when I let off the gas. It seems to be caused by vacuum leak so I hope by changing the shutter valve and shaft and I believe there is a gasket in there as well, I willl restore proper vacuum pressure then the coaster valve will open when I decelerate. I will also change the base seal at the bottom of the carb. too. Then no more backed up carbon causing me to fail the messions test.

Or am I crazy