I have a rx7 1982 none turbo that will not run right in the cold morning's, it starts up and runs with choke half way ok. It's when the choke is not needed and returns that it plays up. I find myself holding on to the choke when it should not be needed. Anything below temp 13c it will ( cut out or splutter ) when i pull up or slow down to go around a corner. It was a 12A and was changed for 13B, not by me. I have tried to run hot air from the manifold into the air intake with a suitable tube, but still runs the same. If the car has warmed up after 8 min of running it still will play up if the out side temp is around 7c. It never gets to freezing here just chilly !
Runs great above 15c likes the warm like me. ;-)
Any one have an idea. ?

 

Sound like you have low speed and/or idle speed, fuel circuit problem. Another possibly is vacuum leaks, in particular the shutter
valve diaphram, mounted under the carb heat shield on the intake. Have the air filter cover off, there are several ports for air intake
or relief. You want to check the ones which are on the #2 rotor side or closest to passenger fire wall. Place your fingers or some
plug which won't go thru the port. How start the engine, see if it still stalls, if it does then the shutter valve is probably , ok. Another
area for air leaks is the intake to engine gasket, usually their fail on either the front end housing or the rear end housing, listen for
high pitch air sound. Please post again if this doesn't help.

 

I should of added its an auto. Its something to do with the cold anyway, maybe valve diaphram that stops moving freely. There is a carb heater with a brown wire feed to it. I dont no if this is right but the voltage to the heater is about 3 volts with choke on maybe that correct or that has nothing to do with it. Connected to the heater is a vacuum/leaver the vacuum works when its running but if i move it back by hand the engine sounds the same. I dont have much of a clue what that is ment to do.
Thanks for some ideas.