What is a cruise valve? What is an over-run valve?

My 1982 rx7 started making an airhorn type noise, and the mechanic said it was do to a faulty cruise valve, but that it didn't really do anything, so they just blocked it off. The next mechanic I took it to said it was an overrun valve. When I asked what happens if I don't repair it, he just said that I should fix it because it is broken.

Anyone know if it is important to repair, and if so, where to buy on at?
thanks,

 

You need to find someone more familiar with rotarys. Sounds like it could be the shutter valve. In my sig line is a link to the onlie FSMs and the carb manual.

Welcome to the foeum and the Darkside.

 

Welcome to the forum. 1st advice either get another mechanic or stick with us on the forum and you won't need one.

As my Esteemed Collegue has already stated, it sounds like the shutter valve that is mounted to the intake manifold. What it does it shut off fuel to the rear rotor during deacceleration to help lower emissions.

To verify if it is the shutter valve do the following. 1). Take off the air cleaner lid.
2), On the left side(closest to the driverside) underneath the air cleaner assembly you will see 2 hoses going to the top of the engine. There will be a small one and a larger one that goes to the air cleaner. With the motor running put your hand over the top of the larger hose opening at the air cleaner assembly. If there is suction there the shutter valve is bad.