SHUTTER VALVE. My experience with this: RX-7 (1982) would not go over 45-50 mph. The whole prolbem started when it started dying at stop signs, but would start up right away again. Loss of power. ANYWAYS - finally removed carburetor. The butterfly valve was stuck closed under the carburetor - SHUTTER VALVE was stuck. Large hole (hose up to air cleaner) that is on shutter valve was crusty and full of crude inside hose. I considered removing shutter valve, but gently nudged it open and gently worked shutter valve back and forth and disconnected shutter vavle HOSE for now. I left shutter valve and butterfly valve intact and connected. Put carburetor back on and drove car....problem solved. I believe the closed valve actually had the car running on one rotor, RIGHT? THANKS

 

I've had my '85 GSL for 5 perfect smog years. Fails miserably at my smog attempts this time. Way rich smelling idle...

The shutter valve is obviously broken since it sucks air at the cleaner at idle. My thumb on the hole opens it up...so I'm thinking something's amiss. Solenoid and lines check OK. (Every plug, wire,cap, rotor & filter is new)

Atkins has the shutter valve part at +\- $100 bucks. This should be the smog problem?