Like it says ^. Its a 12a stock everything. When your under light throttle or no throttle the thing surges, kicks and sputters, at wfo it runs great. Any ideas?? Could it be that shutter valve under the carb? I just want to get it running good so I can go try to trade the 12a and trans for a T2 trans at a local Rx-7 place.

 

Check the shutter valve pipe. (Pictured below) If it's sucking air at idle, it's bad.. Just shove something in the hose. The only price you pay is some small backfiring.

 

she's sucking air alright... But when I plug the line it runs shittier hmmm... Any other ideas??

 

Plugging the pipe hose made mine run rougher too, but i adjusted the air/fuel mix till it settled at 750/800 rpms////still has some mild dead misses at times thou.....good luck,,,,,,

 

Thanks Donna I'll give her a try

 

Check your fuel filter for rust :p

 

Mine sucks air also but my iddle is fine at least 90% of the time. The other time it iddles low and rough, but either way is sucking air through the shutter valve.

 

Stop putting NOS in your air cleaner

 

OOH! how the hell do you fix the shutter valve? mine's bad and i want to fix it.

see this thread: https://www.rx7club.com/vforums/show...threadid=18145

 

Make sure nobody tried to "compensate" for the bad shutter valve.

When I first got my 7, the idle was cranked all the way to nothing(Slacken the throttle cable and watch the engine die) , the throttle cable was tightened to bring it up to 1500 RPM to get over the sputteriness of the shutter valve, and several hoses and wire were disconnected and plugged where applicable. She didn't get miles per gallon... It was the other way around.

Everything was re-routed and put back properly when I got the carb rebuilt and everytihng was readjusted.

 

http://www.mazdatrix.com/c-5.htm
http://www.mazdatrix.com/faq/shutter.htm

13-120A-1480.....VALVE SHUTTER SHAFT...81-85 12A..............$ 24.87
13-1210-N201.....VALVE SHUTTER PLATE...81-85 BUTTERFLY........ $ 8.02
13-130A-1480.....VALVE SHUTTER.........81-85 12A RX7..........$ 63.00
13-139C-1480.....GASKET SHUTTER VALVE..VALVE TO MANIFOLD...... $ 1.20

Better off just leaving it plugged, but if you really wanna. Good luck